Make sure you keep them away from humidity. Over time it can damage the boards inside. That happened with a $400 sale of mine of a brand new camera... it was 15-20 years old, but the internals had gone on the fritz for the LCD display because of moisture that somehow got in the package from being in a basement.
RE: I Don't Usually Thrift, Buy When I Do... 10 Recent Thrift Store Flips Bought For $81.50 & Sold For Exactly $1,000 (12.3x Return)