2001 Ford Expedition repair costs

Engine Mechanical problem
2001 Ford Expedition V8 Four Wheel Drive Automatic

I have a 2001 ford expedition 4.6liter engine that has the number 3 cylinder exhaust valve that has a recessed in its seat. The dealer says to replace the head or get a remanufactored engine. The cost of the head replacement is in the 3,000, while the engine replacement is 4,000-5,000 range. I would rather have the head replaced. Ist that a reasonable price for a recondition head on this car? How much would it cost on average elswhere? Is it possible to do it myself cheaper? Please let me know!