Ebay seller tagex is currently selling a single Power Battles cabinet, complete with decals. The best part? It's currently at $2.25 USD ($45.00 shipping) with only two bidders. How could you not pass up this opportunity? Well, there's a bit of a catch.
As noted by the seller, the cabinet does not "power up," meaning it's broken. So, if you do happen to win the auction, you're expected to get the machine repaired.
If that's not a problem, bid away! If it is a problem, then there's always these working cabinets here and here.