You cannot get an L2500 for anything close to $700 anymore. He can also part out the bass for almost all the cost. The pups, bridge, and tuners are worth something like $500 new so he could get at least 1/2 that and probably more. That leaves the body, electronics, knobs, etc. As pointed out earlier, the body with all the stuff in it wil fetch his $400 back easily, it just a matter of not minding doing the ebay thing. I can't see him loosing much if any on this deal and he has the possibility of graing a +$1000 bass for $400. No real downside in my opinion.
You should probably read this:
http://www.talkbass.com/forum/showthread.php?t=658993
I bought an L-2500 from GC last year. Same problem. Truss rod bullet adjuster was stripped. I got it out myself. Took the bass and a new bullet adjuster to my tech to do a setup and when he tightened it up, the truss rod broke.
Getting a new neck was cheaper than replacing the broken truss rod.
A new neck was $450 from G&L, plus $150, I think it was, for a color-matched headstock. And I had to send the bass to them to do it and they kept the old neck. They turned it around in just under a month.
Bottom line: just based on what I've read here, I would be inclined to assume that, if the bullet adjuster is damaged, then it was probably over-tightened to the point where the truss rod is now damaged and likely to break at any time. So, the only way the bass is worth buying is if you can get it for some price where that plus around $550 (by the time you ship it both ways) is still a number you would feel good about.
These ^. Again, if it winds up being too much of a hassle I'll return it or flip it.
), but the neck is a goner.