Some of the newer electric machines are hard to repair since the boards may not be available. Basically if it has a plug I would avoid it. Even older machines have fallen a lot in value over the last few years. Machines that were worth $1500 - $2000 a few years ago bring closer to $1000 these days. Most of the mechanical machines are not that hard to fix and they are almost indestructible. Unless the mechanism is rusted they should be repairable. That said, if they have been sitting for years they will probably need a little help to operate properly.