So will the cost go down cause generally Rn's make less than Dr.'s right?
If the quality of care is the same as the doctors', then the cost should remain the same. Insurance pays based on a common and reasonable cost, not the salary of the person performing the service.
If, however, the doctor makes more because the quality of his/her services are better, then it's a problem that less qualified nurses are being allowed to do the procedures.
This is an example of the trade-off we would get under a single-payer, government-run healthcare system. The managers decide how much they are willing to pay, and the providers are faced with trying to provide services at those cost points which might involve seeking out lower quality sources of care.
You can't complain about the price, then turn around and complain about the quality when your cost is lower. Good champaign at beer prices doesn't exist.