What if you passed out "smidgets" for each prize? Smidgets are very valuable and must be saved in a very special ziplock bag so they don't get lost! Then, every Friday after Bingo you gather your smidgets and spend the money you are already spending on "crappy dollar tree" prizes and have a social and serve pizza or some other (appropiate for their diet) snack. Or purchase new wii games or cd's or videos...? They still get a prize, and you can use your money for stuff that will be appreciated. (smidgets can be any small token).
Millie