We ran into your problem, rav, when we invited my parents to go along on a Hawaii exchange in a 2br. They absolutely INSISTED they had to pay something and taking us out for a couple of nice meals just wouldn't cut it for them. So we came up with the idea of charging them $50 per night. That is significantly cheaper than the $10 per point, (or even $5). It made them happy and it worked out so well that we figure that when we invite our brothers/sisters/inlaws and their families along on vacation, if they insist on splitting costs we'll just charge $50 per family per night. For us, it's a win/win situation without having to do a bunch of math. Good luck!