And I mean, literally, buying a lens with expectation of it appreciating and selling for more. When I read old mirrorless discussions, I often see touted prices of lenses at far less than you could get today. Mirrorless has certainly brought back a lot of SLR lenses back into the game and will only get more popular. And now Canon is in the game, I see a huge increase even if most EOS-M users will probably stick to EF lenses (one of the reasons I like FD lenses so much is Canon fanboys - my brother's already told me he'd buy my FL55/1.2 if I ever sold it and I was nice enough to tell him over my dead body in polite language ). Is it worth a shot? The obvious risk of course is damaging your investment, and secondly, if you buy a lemon that isn't returnable, but if you can pick worthwhile lenses it should be quite safe? I mean I look at Nikon lenses that seem to go for double the price of everyone else even if they're ugly, worn and fully manual. Then there's the 58/1.2 Noct-Nikkor that seems to only get more expensive every year... So far, I've not bought a lens I've sold for less except Sony originals that obviously depreciate as soon as you take it out of the box. But legacies all went for more and now I'm seriously thinking of moving up a level in prices to get into the $500-3000 range of lenses and prepare to sit on them for a few years while mirrorless markets grow. It's basically antiques trade specializing in working lenses plus having an excuse to try out that lovely Noct-Nikkor Good idea or bad idea?