The head has to be to factory specs per the regs. I don’t know if there is much you can do legally.
I would get an old head from somewhere and find the best shop in Savannah you can. Call around and get some referrals. They should measure all parts and make sure they are within factory specs and replace those that are not. I got a 4 cylinder head redone recently and had to replace two exhaust valves and all the seals. It was about $200. It was not a BMW, so it may not even be a good comparison.
Alex did a head for Damion. Send him a PM and ask him about the quality.
Edit: Did a quick price check on Pelican Parts. New valves, guides, and seals will run about $300 just for parts. Add springs and thats another $250, plus shipping. $650 for Alex’s head is a good deal when you figure labor. Plus you don’t have to run all over Savannah finding machine shops.
John