You are not aloud to pay a woman to be a surrogate for you.
There are websites out there can can give you an idea of the cost. I know that you are paying for med expenses and probably a "compensation fee". I have never priced it, but wish you luck in finding a way to have a child!
The cost is around 50-75k depending on where you go, what agency, and what their benefits package is. You have to count in the IVF expenses which are about 15-20K depending on your situation, doctor, and if you get pregnant right away. Hope that gives you a ballpark!