I picked up a Jiffy White Lightning off CL locally for $100. This thing was used so little that the stickers are still on the drill unit, and it runs great. I picked it up for my buddy, but I just might keep it myself. Ha ha
Just take a good look at it and run it. As long as it wasnt abused, you should be OK. My last Jiffy lasted hard 25 years before it gave up the ghost.
Good luck