Anthem no longer covers Mt Sinai doctors (NY)

I have been seeing a breast surgeon for a benign (pre-cancerous) breast condition that requires semi annual scans - mammo’s and mri’s. In addition, I will see the doctor yearly. Since Anthem is now out of network, how do I find out how much the mammogram and doctor consult is? This may be a dumb question but I have been getting the runaround. Am I able to pay ‘cash’ if I have insurance even though it is out of network or is insurance still required to process it? I have been told that is not allowed. This whole process is a nightmare. Any help would be greatly appreciated!