From the price in the hospital for the surgery of the retinal detachment, it may cost you between $1100 and $ 1500. It is really expensive in some big and top lever hospital. If you have the high prescription, you'd better take care of your eyes, not letting them get knocked. You'd better not do the strenuous exercises which may hurt your eyes.
It is depend on what method to you choose to fix the detached retina. But it is expensive. If you do not have insurance and live in U.S., it may charge $10,000 - $20,000 not including anesthesia. It is depends on where you live in U.S. In fact, most of hospitals have financial assistance for surgery if you meet certain criteria. In fact, you needn't worry about retinal detachment if you do not take some fierce activities.
I am so sorry to know that you have such high myopia. So, it would be wise for you to prepare for this in advance both psychologically and financially. As a matter of fact, it is one of the most expensive surgeries in the world, for it requires intensive technical supports and equipment. Generally speaking, it would cost you over ten thousand dollars. God bless you.