teach correct principles and let them govern themselves

i know i've touched on this subject in a previous blog, and it will probably be a re-occurring theme in my life (because i'm a control freak). we recently received some "just because i love you" money from an aunt of bill's. we allotted each child some money to buy what they thought they needed for back to school. we spoke with them and went through each one's wardrobe to help them see what they really needed. a couple are in need of shoes. we've went garage sale hunting and thrift store searching for the past two days and we have been able to take care of most of their needs, but we didn't find any shoes. i'm starting to get a bit concerned that the money will 'disappear' before shoes are found.
when i was a young women's leader i was told to allow the youth to run the program and i was there to help out. there were times when everything fell through. some of 'my' young women may even be reading this wondering, 'when?'. i'm sure i'm the only one who remembers. these young women are now grown with children of their own, all living very good lives, so what if things fell through from time to time?
so what if a couple of my kids don't have shoes? this is a chance for them to learn how to budget out their money, they can learn needs versus wants, they can learn that flip flops are hard to wear in snow and ice.
letting them govern themselves (at the appropriate ages - of course!) has got to be the hardest part about being a parent - any advice?