430 Price-Determining Formula and Analysis

Here's what $40k per year in tuition buys you. I'm a senior at Emory University in Atlanta, Georgia, and I'm doing a final project in an Econometrics class to wrap up my Economics major. My project examines trends in used car prices and analyzes variables involved in depreciation using (relatively) simple regression analysis.

Though my project focuses on "average" cars with tons of data, on a lark I did some statistical analysis of 430 prices and I was able to come up with a fairly accurate formula to determine values. The variables I utilized should explain factors behind between 82.6% and 84.2% of a 430's price. Thus, using my formula should help you determine what your 430 is worth, or whether an asking price for a car you're considering is fair, with pretty good (~83%) accuracy. Note that the formula is based on asking prices, not sales prices, Scuderias aren't included, and it will be rendered incorrect quite soon as prices continue to drop. Nevertheless, here it is:

1. Start at $226,734.50. (not an average! The average 430 is $183,684.50)
2. Subtract:
- $17,074.30 if a 2009
- $34,148.60 if a 2008
- $51,222.90 if a 2007
- $68,297.20 if a 2006
- $85,371.50 if a 2005
3. Subtract $1.64 per mile.
4. Add $7,515.73 if equipped with an F1 transmission. (do not subtract for 6-speed)
5. Add $3,448.02 if red. (do not subtract if not red)
6. Add $20,656.99 if a Spider. (do not subtract for a coupe)
7. Add $3,648.72 if it has Challenge wheels. (do not subtract for normal wheels)
8. Add $3,824.94 if it's at a factory dealer. (do not subtract if not)

For example, utilizing this formula, a red 2005 F430 Spider F1 with 460 miles and Challenge wheels at a factory dealer should be:
1. $226,734.50 (beginning price)
2. Minus $85,371.50 ('05 subtraction)
3. Minus $754.40 ($1.64 per mile subtraction)
4. Plus $7,515.73 (F1)
5. Plus $3,448.02 (red)
6. Plus $20,656.99 (Spider)
7. Plus $3,648.72 (Challenge wheels)
8. Plus $3,824.94 (factory dealer)
TOTAL: $179,703

Indeed, Ferrari-Maserati Newport Beach has that very car priced at $179,000 at the moment (now sold), so they're about spot on using my analysis. There are some cars out there that are very much high or low, though.

Thought everyone might find this at least somewhat interesting. I don't necessarily want to fuel the crazy pricing-obsessed threads trend, but I'm a bit of a data geek and since I had a little free time I figured I should share. Everyone's always asking what their car is worth or whether a price is fair, so I figured this would be an interesting post - at least for a few weeks until it becomes obsolete!

 

The variable I really wanted to add was Carbon Ceramic Brakes since it was such a pricey option, but not enough dealers mentioned in ads whether vehicles had them or not, unfortunately. It was very easy to determine whether vehicles were red, or convertibles, or had Challenge wheels, but Carbon Ceramic Brakes isn't as simple.

With that said, the variables I did include accounted for a huge percentage of the pricing factors - it's very rare to even get close to 100% because there are always "other" factors involved that can't be statistically analyzed (like whether the seller "feels" like his car is worth more) and of course if one were to truly do it right, dozens more variables should be included - seats, Challenge Grille, Carbon Ceramic Brakes as you mention, plus number of owners, accident history, clutch life, etc. But given a quick analysis of a few variables, this formula does surprisingly well.

 

Indeed - your coupe is almost spot on (you've got it at $165k and my formula puts it at $161k, well within the margin of error - and it has some key options) but your convertibles are far below my estimated value. I'm actually surprised no one's biting on your '06 Spider with 5,500 miles at $170k - that's only $4k more than your gray coupe... and it's got fewer miles!

 

Your point is well-taken and hit on some of my work with other more common cars. I wasn't going to analyze the 430's prices for my class project, but spurred by my interest in the considerable significance that these variables had in Ferrari prices, I decided to look at 430s a bit more in-depth. In order to eliminate 'blanket prices' I did year-to-year regression analysis; here's what it came up with:

2005 models (avg price: $153,381.40, avg mileage: 7947):
1. Start at $151,082.70.
2. Subtract $1.11 per mile.
3. Add $723.98 for F1 cars.
4. Add $1,362.15 for Rosso Corsa.
5. Add $16,511.12 for Spider.
6. Add $11,458.02 for Challenge Wheels.
7. Add $289.39 for factory dealer.

2006 models (avg price: $169,715.36; avg mileage: 5742):
1. Start at $158,686.70.
2. Subtract $1.55 per mile.
3. Add $6,372.65 for F1.
4. Add $2,711.92 for Rosso Corsa.
5. Add $17,331.30 for Spider.
6. Subtract $2,068.81 for Challenge Wheels.
7. Add $5,592.32 for factory dealer.

2007 models (avg price: $190,354.20; avg mileage: 3172):
1. Start at $182,731.10.
2. Subtract $2.68 per mile.
3. Subtract $2,325.34 for F1.
4. Subtract $180.31 for Rosso Corsa.
5. Add $23,989.83 for Spider.
6. Add $2,104.50 for Challenge Wheels.
7. Subtract $1,524.96 for factory dealer.

2008 models (avg price: $220,195.90; avg mileage: 1777):
1. Start at $190,377.90.
2. Subtract $2.44 per mile.
3. Add $7,737.06 for F1.
4. Subtract $1,850.90 for Rosso Corsa.
5. Add $28,177.74 for Spider.
6. Add $4,690.35 for Challenge Wheels.
7. Add $5,862.61 for factory dealer.

I've bolded in red some problem statistics. The issue with year-to-year projections is that the sample is much smaller. While the overall sample looks at around 200 cars, that only ends up being around 50 cars per year, so some odd stuff can skew the data. For example, the 2005 Challenge Wheels data is statistically significant, but is probably skewed by the fact that only 8 of the 2005 F430s for sale have Challenge wheels, including the 5 most expensive - statistically significant perhaps, but not a large number and probably more correlatory than causatory.

With that said, I added considerably more 430s to the sample this time around in order to reach a higher level of statistical signifiance and came up with new numbers. They still account for about 84% of the 430's pricing factors, but they're a bit tighter, reflecting the higher sample size. They are:

1. Start at $226,381.90.
2. Subtract:
- $32,497.80 for a 2008.
- $48,746.70 for a 2007.
- $64,995.60 for a 2006.
- $81,244.50 for a 2005.
3. Subtract $1.71 per mile.
4. Add $6,502.94 for F1.
5. Add $612.62 for Rosso Corsa.
6. Add $21,502.34 for Spider.
7. Add $2,275.76 for Challenge Wheels.
8. Add $2,371.30 for a factory dealer.

Based on what I know about your car, hardtop ('05 430 Spider 6-speed, Rosso Corsa w/16.7k and Challenge Wheels), this would put it at $140,791.12 - much higher than the previous estimate but probably closer to a correct asking price, given that the average price for a 2005 F430 is $153,381.40 - and yours, while "high" mileage, is a Spider which helps tremendously.

I do agree that my formula doesn't do mileage perfectly. The main problem is that my formula is linear while car values aren't. My formula would assume that a 100,000-mile car is essentially worthless (if not negative in value); of course it's not. In general this tends to be true with formulas like this; outliers tend to cause trouble. However you can see that - just as you theorized - mileage affects value considerably less as year goes on in the above formulas - for 2005 cars, it costs just $1.11 per mile, while it costs $2.68 per mile for 2008 cars.

 

Despite a relatively small number of Scuderias for sale, I was able to estimate prices between 78.1% and 82.1% accurately, which is a great figure. Here goes:

1. Start at $293,150.30.
2. Subtract $21,007.30 for a 2009 or $42,014.60 for a 2008.
3. Subtract $2.06 per mile.
4. Add $57,783.65 for the 16M.
5. Add $2,493.56 for a factory dealer.
6. Add $12,556.40 for the stripe.

Most Scuderias for sale are pretty spot-on with my calculations, with the huge majority (about 70%) within $10k of these projections, or less than 4% of the value of the average Scuderia (which by the way is $272,038 with 1707 miles). The only caveat I have about Scuderia prices is that there are currently only 2 used 16Ms on sale, so while the data is still pretty accurate it'd be nice to have a larger sample of convertibles.

Since I ultimately decided to run statistical analyses of 430 values with the intent of adding it to my schoolwork, I did run similar analysis of 360 values for comparison. A thread in this section is forthcoming.

That's what makes the Ferraris so interesting - the options on a normal car decrease in value over time; after about five years the only things that really matter are navigation, drivetrain, and engine choice. Sometimes a third row or DVD player will play a SLIGHT part. But the Ferraris are amazingly sensitive to changes in these variables. It's been fun to play around with these models and see just how amazingly sensitive they are.

EDIT: Of course, I'm only looking at the most significant options (F1, wheels, Spider/coupe) which is kind of the point since they are most likely to affect value.

 

Indeed. And if yours is a coupe with standard wheels, with the "revised" overall formula with more vehicles in the sample, I get it at:

226381.90 - 81244.50 - 1.71(16,700) + 612.62 = $117,193.02

Which works out to nearly exactly the same as before!

 

Agreed. I wish I had data on more selling prices than a few eBay sales here and there.

Also agreed. The only problem is that you'd need to build a formula that could pull the data off AutoTrader constantly which is above my skill level! That said, it would be a very nice tool to have both for buyers and for sellers. Another interesting variable might be 'number of days for sale.' I'm not sure if AutoTrader has such a feature, but I imagine there's a negative correlation between price and number of days for sale, as dealers lower prices to try to move aging inventory.

 

Sorry for bumping both of these threads, but I don't check the 360/430 section as often as I should, clearly!

I used about 160 cars for this regression analysis and about 180 for the 360's if memory serves. I would love to use auction data and completed sales on eBay but I can't imagine there's even enough published data for statistical analysis. In the interests of statistical discovery I would love to check out registration data or dealership sales data to find actual sales prices, but of course that stuff really isn't available.

Thanks for the kind words - and for the record, I did eventually get a 95 on the project.