Early 944 cookie cutters on a '87 924S
 

Will cookie cutters from an early model 944 fit a 1987 924S without any modification? Also, about how much would a set of 4 in good/decent condition, with centercaps and decent tires go for? Figure $250-300?

No, they won't fit - the early offset wheels will mount too far "out", the tires won't clear the fenders. You need late offset wheels, up to 7" width fronts and 8" rears. Phone dials can be found at reasonable prices, or you might consider 6x16 Design 90's, there seem to be quite a few of them around at low pricces, as compared to the 7's and 8's.