Maybe it is a difference in marketplace. I was in Ohio when I was looking for someone local to work on my cylinder heads. Still lots of people in the area that worked for GM when the Firebirds and Camaros were still being produced in Norwood. The gentleman who worked on my heads (and who I saw at the Co-vention) has been porting heads for 30+ years. He doesn't have the reputation of others, so that is likely keeping his prices down.

Looking at SD Perf pricing, it is high to me.