Sure, usually people that sell things like vending machines will sell the types of ATMs you see at convenience stores. They aren't quite the same as the ones the banks use, but they still hold cash.

They appear to have them for sale on ebay...

Yeah pretty much.

I don't know about buying one from a vendor, but I bet if you knew the right ahem ring of people you could get a... used... one for whatever the blackmarket rate is