I have been trying to find a spare battery pack for my Ryobi 9.6V cordless screwdriver. The one that I have works just fine, but after a couple of hours of intense use, especially if you haven't kept it recharged, it gets a bit weak. So I went to Home Depot. Nope! They have moved up to systems that use 14.4V and 18V batteries. On their web site? Nope! I called one of the local battery specialty stores--they could rebuild mine (which really means taking it apart and putting in new batteries into the pack), but they didn't have any that I could just buy.
But on eBay, I found the exact item that I needed, new, still in the original packaging, in Utah--someone has dozens of them, probably the result of getting a bargain when Home Depot stopped carrying them--and it cost me $17.40 including shipping.