unless your trans has been beaten hard and put away wet, you may be able to get away with a poor mans rebuild. just pick up a single sincro, or even a used one. All the t5's I take apart, i usually find sincro 1 and 3 are hardly worn. Nothing wrong with using a used syncro so long as you inspect it.
bearings last a long time, you can inspect and re use too. If you're lucky, you can get in there, and just swap in a syncro, and put it all back together re using everything else. Having said this, I've always used all new parts, but then again, I'm building trannies for my friends and other locals. However, when I nuke one myself racing, better damned believe I'm gonna dip into my used stash of parts.
It's not too much work (at least not after I've done it time and time again)....
just thought I'd mention it, because a rebuild kit quickly turns into a $250 rebuild kit (hanlon price)....along with a $75 second gear, and a $33 slider. $450 later, you're ready to go. I have YET to pull apart a t5 and have the second gear dog teeth not all ground to hell. I've replaced second every damned time I rip another one apart
I have to replace the 1-2 slider about half the time.
be prepared to go all the way or "try" and bandaid it...you may be ok.