Couldn't really say pringles, cos i did valve job, cam, porting and raised CR all in the one hit. I think the stock valve job is a 3 angle. When i had mine done i think it was approx $5-7 per valve/valve seat.
You can get a 5 angle cut done, from memory that was about $10-12 per valve.
You would have to contact a head workshop for more accurate pricing.