They're right, a head this worn calls for 6 new exhaust seats, all new valves, new guides, retainers, locks, springs, seals, head milling, the works. Cost me $350 back in '97 when I had it done.
Make sure that the machinist sets the spring installed height and spring pressures correctly. Don't just shim up the valvespring if the seat pressures are low. Replace the springs if weak.
good luck
chip
