What I've found in the pricing of 'desirable' cars, or at least the ones I desired, there's a bounce...
Depreciate, depreciate, depreciate then they hit the price point where they're owned by those that would never have wanted them at their original sale price (rather than saving etc), so are trading on their once exclusive nature although the cars are not exclusive through price any longer...
These buyers are not enthusiasts and often cannot afford to keep their 'super'cars super anymore, the first sign of trouble and there isn't a quick eBay fix or their local mechanic mate can't fix it for a tenner then the car gets bodged and sold 'cheap' to an unexpected punter who thought they got a bargain - often they're at the top of their budget and so niggles often turn into major or growing faults.
Thus a two tier market forms, not based on mileage, but on condition; this is where we are now.
The bounce?
This is when enthusiasts either buy these bodged cars and bring them back up to condition or they get so bad that it's obvious they're knackered and they're broken for parts - this then leaves only excellent examples left and the price skyrockets.
We're hitting the split between excellent examples and eBay specials with the GS now, the bounce will happen in the next few years.
IMHO.