Allow me to make a long story short...
2 years ago, I bought a 1978 Grabber from this guy my guitarist worked with and paid less than half for what you'd pay for it on eBay; the only thing is, the neck (truss rod, rather) is irreparably warped. It is playable, but the action is so high I typically get hand cramps by the end of a set and it cannot be adjusted. I've taken it to a local luthier who said it'd be $300 to fix it.
Now, I do not really have $300 lying around right now but I HAVE read about people having the same problem with the same model bass replacing the neck altogether, like with a P-bass neck (see:
Sage Guitars). I checked out Warmoth but I'd still be paying about the same amount of money if I went with the luthier.
Any thoughts or suggestions before attempting something similar? Is there a good yet cheap way to obtain a P or possibly a J neck that might fit my dear G3? Or should I be patient and save up to have the luthier fix it?