That's a steal. I doubt you'd find a shop willing to do that for under $1k at the absolute lowest. It's certainly possible to get that job done in 6 hours, but if it's been a couple decades since it's been done it could easily take much longer if any of the parts don't cooperate. I would say 6 hours is the absolute minimum, that's somebody that's done it before, has some of the special tools needed, and everything goes the way it's supposed to. Torsion bars have to come out, break loose the ball joints, control arms, strut rods, shocks, then press out bushings, then press them back in, ball joints, tie rod ends, reassemble everything, reset the ride height, reset the alignment, etc, etc. Personally on a car that NEEDS a front end done I wouldn't plan on that taking less than a couple days. One problematic torsion bar or camber bolt and that one thing might take 6 hours.
Can he do an alignment on it? Because you'll need one