Buying an XDR-F1HD on eBay
Ebay is the easiest place to find these for sale but prices & condition vary wildly. Some ebay sellers have no idea what these are or how to test one properly. They plug it in, the display lights up and the clock flashes, so they call it good. You could be buying a lemon in distressed TECHNICAL condition that has NOT been properly checked out and might not work correctly.
Some questions to ask an ebay seller: