Re: What do you guys think this could be.
It's not a hard problem to diagnose.
The fact that you can start it implles that you can push the clutch in and it starts....but when you let it out and the tranny is in neutral, it dies. That means you clutch is ok....so, yea, your tranny is shot.
Nnw, if pushing in the clutch has now effect, then yes, the clutch is suspect.
A little advice...if you have to swap out the tranny, do the clutch as well....not that much more work...