i would allow 100 for each weekend camp, between 2,500 and 3,500 for fee (including uniform, move in, and whatever other fees they throw at you). plus your personal travel expenses. plus i know that i had to have a new wardrobe of clothes to march in (300 of clothes and shoes). then i would do what everyone said and allow 200 for tour money. so all in all i would say 4000 plus personal travel expenses.
its a lot of money, but there are lots of people that are willing to donate