Junkyards cant sell the parts from the c4c program, same with the transmissions and rear axles, this is how were saving the world, cause all those cars were completly junk, and if you use any part of the drivetrain in another car, your part of the problem not the solution.
If it were me, i wouldnt pay more than 150 bucks for those parts. A visual check of the cylinder heads is not going to tell you what kind of shape they are in. You will definitly at the very least have to have them re-surfaced at a machine shop, and when they are there who knows if they are gonna need a valve job, valve seals, springs or even if the valves are straight.