yellow99gt

I just picked up my car, yellow 99 gt 5spd, yesterday. Third gear is super hard to shift into, sometimes not even available. Seems, according to some research, that it is a damaged shift fork? No grinding, just hard shifting. Am I correct in my theory? If that is the problem, how much should I be looking to pay to have it fixed? Does anybody have any experience with this problem? As soon as I have it fixed, I am going to get an aftermarket shifter (steeda tri-ax seems popular).

The car has 37,000 miles and everything is bone stock except for air filter (K&N filtercharger) and I paid just under $11,000 for it, so I have some left for fixing.

Thanks for your help!
Nat