Sounds like lots of fun, but just for you information many states have laws about money and bingo. In AZ, many of the RV parks cannot have money on the table as this is gambling. Does not make sense to me but all it takes is one person to turn you in. As to the 15.00 idea, this could be a little pricy for someone on a fixed income. In several of the RV parks, we have done brown bag bingo, food (cans/boxes) bingo, candy bar bingo, etc. We have even been asked to look around our RV ( or your home) and bring something you now longer want. Other ideas are stationary, boxes of cards, writing kits, knick knacks, even something someone gave you that you really did not like a unusual figurine, ugly ash tray. Hope this gives you some ideas.
Marie