One thing to know is that the prices of many machines had dropped over the years. Older electric machines that used to bring $1000 now bring a few hundred. It would help to know which machines you are looking at since many of the common ones (Mills Hi-Top) machines have always been under $1000 while the better machines (Rol-A-Top) still can be over $2000.

Most machines only need oil on the cylinder that controls how long the reels spin to get going. Or the coin feeder is jammed up which is a simple fix. Good luck.