You need to find another vet. This price is crazy!!! My turt had an ear abcess several years ago. It only cost me $85 to have the surgery. It is a very simple surgery. They give a little anesthesia and then just make a small cut and take out the pus. They do not even stitch it. It remains open to clean and it heals on its own. I would give that vet a piece of my mind!!
It does need to be taken care of but you have time to shop around. Keep us posted