Cash or Credit on Castaway Cay?

[mog]

I didn't really have time for shopping at Castaway Cay during our last cruise, so I don't remember - do you pay cash or charge to your room in those little shops (T-shirts, etc.)?
I'm wondering because I'm thinking that Disney Dollars would be a good Christmas gift for my kids and I wondered where besides the ship stores they could charge to their cards and use Disney Dollars to pay it off.
thanks

 

[Diva of Dragons]

Hi! Everything is charged to your room except stamps at the CC post office.