Lots of sentimental advice here.
I sold the two Leicas below on Craigslist last year for good money. Why? I simply wasn't using them, and I'm getting to a point in my life where accumulating stuff doesn't have the appeal it once did.
These things are unlikely to go up in value. The only people buying them are art and photography students. Why not give someone else the chance to be their custodian, rather then have them gather dust in the attic?
