To my knowledge, events like the senior trip are funded by the class treasury for that grade. The class treasury is financially maintained through fundraisers and other donations that the students themselves organize. If the Potsdam senior class this year can afford to go to Florida, then the vast majority or all costs for the trip are covered by money they have gradually raised for the last three years. While you could argue that technically this is just taking out of their parents' pockets over a longer period of time and in smaller donation-sized amounts instead of all at once, many fundraisers come in the form of selling items to their neighbors and friends. For example, the freshman class this year just had a fundraiser to sell pizza kits to their neighbors and family through the school, and apparently this same fundraiser has been going on for a long time. Thus, for the most part, the money being used for this trip is not somehow coming from taxpayers or their parents - it is the result of efforts made by the students over several years, so they're not exactly acting as if they're entitled to it.