FF Leaky Strut Life

I have my FF at my AD to have the summers swapped and I asked about lowering the car on the stock coils to a lower seat, they sent me back photos of leaky front struts and how if they lower it it'll wear them down faster. Ok fair, no worries I like the ride height just fine anyways. But, I've had plenty of coil set ups in my life and they've ALL been a little "sweaty" but they're saying this is a bit more than that (photos honestly to me I can't tell).

Car has 35k on the clock now so these things are gonna start needing replacement and what not but

a) has anyone replaced front struts on their FF, what was the cost? (I obviously will not be doing this at the AD and go to my trusted indy)
b) how long should coil struts last? I can't say I've ever actually replaced one before. The Olins on my Mini currently are the same now for over 20k and on inspection they are "Sweaty" at times but nothing I'd be concerned with

Also he said one of the rear knuckles on the bushing is worn (it wiggles and there is a slight tear in the rubber). I REALLY don't want to deal with replacing that right now as well, but I'm not trying to skimp on servicing my ferrari either. Any experience with this? I personally have not felt anything out the ordinary when driving, car has been rock solid and I might have taken it up to a speed I shouldn't have and it was as planted as the day I got it.