Need a ballpark number please...

they don't have an 89, but here is for an 88 as a single point of reference...not sure how much I'd put into any of these online estimates though.

Price Guide Report

 

The Sports Car Market guide shows $27.5-$55k range, a pretty big ballpark. Adds $5k for manual.

The 412 sutomatic at F40 Motorsports in CT (Wayne Carini) seemed to pop up and then shown as a "Sold" vehicle pretty quickly within the last week or so with an asking price of $45K.

Someone here saw and drove it and said it had good power, a couple of minor paint issues, a leaky exhaust and a slightly vague steering feel above 55 mph, indicating a need for some front end work. He called back for further information a day or so later and was told it was sold.

Manuals go for more, say $5-8K as a SWAG.

Here's the latest 411:

https://www.ferrarichat.com/forum/365-gt4-2-2-400-412/479570-87-412-auto-sale-ct.html#post143788284

 

This is how that appraiser arrives at his numbers?
BIG range for this series cars, that and given the 1-6 scale is subjective the only thing I'd offer is "not enough information". For example; A scratched or cracked windshield on a muscle car is a few hundred dollar knock, on these it's s few thousand, if you can find a replacement.

 

I believe Hagerty adds 25% for a manual.

 

The car in this thread sounds pretty similar to the one he is looking at. According to the thread, the car sold for $55k although it appears it went to a dealer. Hope this helps.

https://www.ferrarichat.com/forum/ferraris/471458-ferrari-412-blue-chiaro-blue-interior-5-speed.html

 

In that case I'd like to buy him a beer

 

That car looks stronger than a 3+/2-