Xbox one Power Supply Brick Battery

very tricky my friend. I suggest e bay or something like that for your old xbox. Good luck!

I would look at options are available for you for the device at
Microsoft Device Support. Otherwise, for the original Xbox One the original power brick is no longer supported or manufactured, so you're likely not going to find one via the Microsoft Store. If they don't have it available via the Device Support, then
I would look at what is available on other retailer stores and see if they do have official ones available for sale.

Unfortunately, since the original Xbox One is no longer manufactured, finding a "new" official PSU(brick) may be unlikely.

Your best alternative would be finding a used PSU at a local pawn shop or Gamestop, as you mentioned.

I think there aren't any, you will have to buy generic

Hi there you may have to gamble with an eBay purchase...other than that perhaps consider buying a cheap 2nd hand console with the brick included