What other options do I have to treat my endometriosis?

I am 26 years old and was diagnosed with endometriosis in 2006 when I had my tubes tied. I have been on several different types of birth control and currently I am taking Aygeston to stop my periods to try to control the growth of the disease. We tried to get me on Lupron but my insurance won't cover it and it will cost around $1000 for the 3 month treatment. My ob/gyn said I will eventually need to have some other kind of surgery, possibly a total or partial hysterectomy. I'm scared to have that done. My sister had it and she is better. He said that because she had it my chances of developing it when up about 70%. I live in okc, so if anyone knows of a good gyno so I can get a second opinion or has any advice or suggestions on what I should do it would be well appreciated.