I admit it, I am an eBay addict. I have bought parts for cars that I thought I might own because I thought it was a good deal. The one part I would never buy are used brake pads. It would be like putting on someone else’s used underwear (which you can not sell on eBay). I can understand buying used high performance pads for an odd ball vehicle, but used pads for a 1994 Chrysler Voyager or 1984 Corvette?
Most junk yards will not resell worn brake pads due to the the liabilities. Used pads are unsafe because it is unknown if the pads were exposed to extreme heat or contaminated by brake fluid. One listing showed a set of brake pads where you could see the friction material delaminating from the backing plate. (bottom pad, in the middle)