I don't know why this is so hard for retailers to figure out. Valve has an excellent system. Let me give you a down payment, five dollars, ten, whatever. Put my name on a list and when its my turn to buy give me a few days to purchase, and if not refund and move on to the next person.

It's like all these retailers forgot backordering was a thing.

They could even store the address and limit to one order per x period of time.