Surrogacy is getting more and more difficult nowadays. Recently surrogacy was outlawed for foreigners in India. Many other third world nations are also following this example. Right now it is legal only in a select few countries, such as Georgia and Ukraine.
It shouldn't be at the expense of other people's well-being. It is something that really needs a deeper discussion. I remember seeing news of straight couples before that would ask relatives and friends to act as surrogates for them. That might be a better way than paying women in third-world countries though there maybe problems of their own, since the egg/sperm donor is known.
Maybe go buy some eggs/sperm from a bank, and then IVF a relative? I guess that would be better since the donor is anonymous but the surrogate is someone you know and wouldn't exploit.
Surrogate motherhood is not correct, the child should have normal parents. If gays want to have a child, then they can be treated and create a normal family in which they can give birth to a child naturally.
There can be arrangements for that. Of course the problem would be the biological parent possibly meddling with the way you raise your child. Just look at separated straight couples.