I'm looking at a Yashica 635 TLR with the 35mm adapter, mask, original leather carrying case, original manual, and a Focal brand flash attachment. The asking price is $100, which I'm comfortable with. But, I've watched these on eBay for more than a few months now, and I've seen them go for as low as $45, and as high as $250. Even parts cameras sometimes go for $50 or more. In addition collectiblend.com lists them as about $100 for average condition, and mint condition being closer to $250. Since I've never used a Yashica TLR, when I inspect the camera are there any specific things that I should look at to assess its true value? It seems to have a few extra knobs that I'm not familiar with, so I'll be heading over to Butkus' site to check out the manual. I'll check the overall condition, and shutter speeds if I can figure it out, as well as the lens quality. Were these things built pretty sturdy?