Perhaps I misunderstood the question.
STT and NESBA don't race - only trackdays.
last new set of tires I bought was $253 for the pair, and mounting was free. I've never raced.
I have not done track days with any of the smaller organizations. It would not surprise me if they charge more, so that could be where i'm misunderstanding.
but heck, if you're going to the track with any frequency, even if you don't want ot ride with STT or NESBA, consider getting a membership ($35 for STT, and $50 for NESBA if you wait until their December membership drive). the tire discount and cheaper (or free) mounting will cover the cost of membership after 2 sets of tires.
'93 CBR F2 track slave
'97 EX-500 daily ride/makes the F2 feel faster than it is)
"track riding makes heroin addiction look like a mild craving for something salty."