I agree with you Greatnan and glammanana. When my children were 13, I handed over to them their school dinner money, child benefit and established pocket money, and suggested they start learning to budget their allowance to take account of lunch, entertainment and clothes. I was always prepared to step in and help out if they didn't get the hang of it, and would occasionally buy expensive items like shoes, coats, and of course school uniform.
They did quite a bit of ducking and diving - started making lunch boxes up for a start! I noticed I was giving more lifts in the car to save bus fares. Then, each of them supplemented their allowance in some way, asking if there were extra jobs they could do and offering to do things for neighbours, got paper rounds, younger brother started working with older brother attending computer fayres and got paid for Sunday mornings, one got a backroom job in the local Spar shop, putting stock away, another did shampooing in a local hairdressers. They managed very well, and their social lives didn't suffer, they were able to buy things they would have had to convince me about, and they learned about the value of money.