He is worth it but it's only for those who has to have an F2 in perfect working condition money not important. Now there is no Sover Wong for the F100 but assume there is and he would normally charges $500 to fix an F100 would you recommend the OP to send it to them if his camera is really broken?
It's never easy unless you've done it several times before. But with good guidance, it's certainly doable. Provided you devote yourself to it and know your limits (which can often be expanded).