Last time I checked, the parking fee was $6, and it is refundable if you spend over a certain amount in the sit-down restaurants and stores which are located OUTSIDE the amusement park (Breakwater Cafe, Boathouse, Dominic's, Breakers coffee shop, camp store, marina store) or are a registered guest in the campground or in the Breakers or Sandcastle hotels.
I do not know if the TGI Friday's inside the Breakers Tower is an eligible location for the parking "refund". It's actually more like a $6 discount on your $20 purchase or something like that.
I say that the parking rate is $6 "the last time I checked" because the last two or three times that Cedar Point raised the parking fee, they did so in mid-season.
--Dave Althoff, Jr.