With respect to pretty much most brands of 35mm SLR lenses, we have the Micro-4/3rd's revolution to blame for prices going up. Even pre-AI Nikkors that used to go for $25-$50 are now going for $75-$100, sometimes more. With respect to the Nikon F3 bodies, I've seen the opposite happen. At least, at brick & mortar stores (and KEH). Prices are going down. Back when the dump all film cameras craze started, the cheapest I could find an F3 was about $200. Well-used F3 eyelevel with lots of brassing, a cracked frame counter window, and light leak into the prism from a damaged shell. Today, I can get the same camera, with less cosmetic damage, but a missing AE-L button for $95. KEH still has BGN grade F3's and F3HP's in the $80-$100 range.

eBay tends to be all over the place. Most of the higher priced items, if you look at completed auctions, you'll see them relisted multiple times with the same price. It's as if the sellers don't really want to sell their gear, so they put up an inflated "feeler" price to deter someone from buying it. Case in point, there's one eBay seller in California who keeps selling a couple Nikomat FTn bodies for $300-$400. Ones that aren't in the greatest shape. I can get similar condition bodies from KEH in a lot of 5-7 bodies for $50...

-J