I think that the IROC Camaros of the late 80s are about to become that exception. Ones with more rare options are starting to go up in price quite rapidly if they are in good shape.
If you live somewhere that has a relatively large white trash population (sorry, not feeling too politically correct this morning) then the prices are already going up. Last fall I saw a '90-'92 IROC, with something like 60k original miles, going for $7,000!?! Sure it was pristine, but that's probably half what the car cost new!
The '78-''81 Chevy Malibu has also gotten pretty rare and people want silly amounts of money for even rough examples. Like $1500-$2000 for a barely running 4 door. Fortunately other '70s-'80s fullsize GM cars aren't nearly that bad. Cutlasses, Regals and Monte Carlos are still plentiful and cheap. There used to be a guy in town who restored G-bodies, mostly later Monte Carlo SS'. But I'm pretty sure he went out of business. He just charged too much for the cars.
The prices on 850 T5-R's have been going up a lot. The biggest problem is that with only 2,500 produced a lot of them are now in collectors' hands and will never be put back on sale.
You've got to be kidding me. I passed up a green wagon for, iirc, a little over $2,000 this winter. It had a ton of miles on it and was a little rough inside and out. I didn't even take it for a test drive. It was the best thing for my wallet, but I had no idea they were rare cars.
Discontinued modern engines with computers, injectors, and direct ignition will be more expensive to maintain than discontinued classic engines with carburetors and distributors.
True. Just yesterday my truck wasn't running quite right. After a few minutes of poking around I popped the distributor cap and found some corrosion on the rotor/contacts. Cleaned them up with a wire brush and the truck runs fine now. A modern car starts running rough ... and it's time to break out the diagnostic computer, work through a list of 20 different sensors that could've quit, etc etc. Not that I don't like new cars, I just dread maintaining them. And that's
now, nevermind when they're fifty years old.