I just bought an 89 with 188K in really good shape but a bad engine for $1000. I would have paid $1500-2000 (maybe) had it had a running engine. Maybe another $500-1000 for the low mileage.
So in my area $4200 would be waaay too much.
Other parts of the US could be more, or less. Areas like the PNW are really high.
Mine has a real solid frame too, which is rare in my area (and that's what made it worthwhile).