big money fight has begun over the big money at stake when you use you know debit cards. correspondent molly henneberg reports it affects how much you pay for things that you buy. reporter: every time you use your debit card, the bank or company that issued the card charges the store a transaction or slight fee. on average, about 1.14% of the purchase price. but a bill passed by congress last year set to go in effect july 21 would allow the federal reserve to cap that slight fee possibly as low as 12 cents for purrtiation. a move welcome by the national retail federation that calls the fee a hidden tax. this is a classic example of a broken market that desperately needs some government intervention. the banking industry says the fees cover technology and fraud protection cost. contend that this price-fixing by the federal government will not allow banks to cover cost of doing