Worse case scenario you've got $2500-4000 in parts money just for the engine and diffs. With 1st gens becoming harder and harder to come by the possibility to part the rest of the truck out for a substantial amount is quite possible if you're willing to put in a little sweat equity. Hell, I just paid $30 for a couple small pieces of interior trim that are probably worth $2 but I couldn't find them anywhere.
Of course I'm not advocating this by any means but it is possible. I don't know that I could stand to stare at a half parted 1st gen in my driveway but a 6sp 3rd gen sure would make it easier to look the other way.