To charge, or be charged, several unexpected small amounts of money, often in the form of fees, taxes, or related expenses to a venture, which when taken as a whole add up to a significant unexpected cost
It seems like a great offer, but they will just nickel and dime you until you've spent more than retail anyway.
nickel-and-'dime to not give enough attention or money to something, with the result that it is not dealt with effectively. unimportant or involving little money