My team never faced this kind of restriction by the school, but over the summer we registered our parent booster club under Parent Booster USA
http://www.parentbooster.org/. Previously, all our money went into a school account, and I'm not sure how all of it worked, but it took a lot of paper work to use money and there were restrictions like no school funds can be used to buy food. Registering as a booster club was a win-win: we have an account separate from the school and can therefore use our money however we need to, we are a 501c3 so businesses who donate to us get tax breaks, and in your case, you would be able to raise and spend as much as you need. I believe there is a small annual fee/registering fee to register for parent booster USA, but it is a fairly easy process to go through. Let me know if you have any questions about this.