I started giving my oldest daughter charging priviledges when she was 16 years old. They had a set amount each day that they could spend,and after that,they had to use thier own money.On our last trip this past January,I also gave our 14 year old the same priviledges.There were just to many times where the kids went thier own way,and the parents went another.At 19 and 14 years old,they are able to get around the parks very well with the busses.They knew that they could charge souveniers they wanted,but at the end of the day,we took account of all the reciepts and if they bought something other then food or drinks,they had to give us the money for it.It worked out pretty well for us this way,and they never really spent too much money anyway.I do recall one time however where they spent something like 18.00 on 2 milkshakes at downtown disney.If I had been with them,I would have said that was too much money just for 2 milkshakes,but since that was all they charged that day,besdies thier lunch, and didn't spend over the amount we set,I didn't get too upset over it.Actually,I was pretty proud of them,as they never once went over the set amount they could charge each day,and actually came well under. So at the end of the trip,as a way to reward them for thier good budgeting,we allowed them to spend whatever remained in thier daily budget on souveniers,and they were estatic about that. But you do have to know your kids and trust them on something like that,and as mine are older,I felt that it was a good way to show them our trust.