Zirconia upgrade charge

I am expecting to get a crown. I have Anthem Blue Cross PPO. I have read other posts from several years ago about this topic, so my apologies in advance for repeating old news, so to speak, but I remain confused.

My question is: Can an in-network dentist charge the extra "zirconia upgrade" fee (i.e., $350), when they are already billing for the crown (porc/ceramic) itself (i.e., D2740) for $2000 along with buildup/pins (D2750) for $500? I am reading online on reddit and elsewhere how this extra upgrade to zirconia fee is potentially a violation of Anthem's PPO's contract with their in-network dentists. If this is not allowed, how do I state this to my dentist? I do not have that much money. I am not sure I can afford the cost of the crown with buildup even after the insurance is applied here. The extra fee the dentist may want is over the top of what I am expecting. My last crown with a different in-network dentist did not charge this fee, but I still got a zirconia crown. All back molars we are talking about here, so I am thinking they are/were medically necessary. Thank you for any insights.