Only very high-end labs would charge that much to make a dentist a crown. And that would be the total bill for the whole crown, not a surcharge on top of another fee. Many dentists charge an extra fee to make a "white crown" or one with no metal or some other "upgrade". It is commonly done when a patient has an HMO type insurance that pays the dentist a reduced fee for a basic metal crown and the dentist looks for ways to increase the fee with "upgrades". Not sure that is what is going on, but that's my guess.