My wife and I have a simple arrangement: what ever I spend on my planes she gets to spend on whatever she wants. However, it doesn't seem to work in reverse. When she spent a lot of money on a replacement engagement ring (long story), I figured I was well on my way to a 1/3 scale P-38 . Then she told me that didn't count.

For the most part, as long as money is fine, every one is well fed and sheltered, and we have breathing room in th bank account, I can pretty much spend what I want.