Our son is a 4* so we're only a year past where you are now. Unless something has changed in the last year the only money we have paid IN TOTAL is the $250 we sent our son to USAFA with as pocket money.
New cadets will be advanced a few thousand dollars in cadet pay once the school year begins to cover the cost of their laptop computer, uniforms, etc. A certain amount is then deducted from each future paycheck until that advance has been fully repaid - I think towards the end of sophomore year - but no, you do not have to put up $2,500 or any other amount of cash deposit.