I'd like to play with some adapted lenses, but I'm not really familiar with all the myriad options and what I might want. Here's basically what I'm looking for: 1) Cheeeap and easy to find. Like, under 50 bucks cheap. 2) Mostly primes, ideally relatively compact ones. Reasonable quality, at least moderately competitive with the native primes. 3) All on the same mount. I don't want to buy a mix of adapters. I've gotten a sort of vague sense that I might be happy with Leica M mount, Pentax K mount, or C mount. Not too sure.