Help me buy parts for my tranny

Alright, my tranny works perfectly besides no third gear. For the past year or so its been slowly going out. It started out just popping out every once and a while, usually on highway exit ramps, when I was off the throttle or on it very light. It eventually grew worse, and started grinding going into gear on 5 of every 10 2-3 shifts just estimated. Progressively got worse, but it always went in and stayed in if I was WOT, never gave me a fuss at all when racing, just slow putting around, even would stay in 100% of the time if I didn't let off the gas 100% when I shifted... I usually avoided 3rd towards the end, and one day accelerating at ~75% throttle on the express way, hit third and it ground pretty violently, and wouldn't go into gear. Now it won't go into third at all..

So what parts should I buy, and where should I get them? I'm on an extremely tight budget, and just want factory replacements, unless aftermarket is just a few bucks more. I'm also getting a steel shift fork off a friend whose dads gonna do the work, he wants 20 for the fork and 300 for the labor.

**** hit the fan last night. On my way home it started making all sorts of nasty noses, clunking and banging around, grinding, just nasty all around... I got video of it, will post later.