"Surrogacy is as old as the hills."
Is it really? What is the earliest documented incidence of surrogacy? At what point was humanity able to extract an egg from a woman, fertilise it with sperm, implant this into another woman, and this result in a healthy living baby?
Surrogacy is not a natural or "old" phenomenon, and even if it was, that doesn't automatically make it right.
"If surrogacy was banned, no gay male couple could have a child who was biologically related to one of them. Those who want a ban on surrogacy, are you happy with that scenario?"
That's the thing, isn't it? A patriarchal society just cannot bear men not getting what they want.
A gay male couple could adopt or they could try to make a co-parenting arrangement with a single woman or lesbian couple who would be willing to accept their donor sperm. Of course they might not be able to find/make such an arrangement. In which case TOUGH.
I can't believe people have such difficulty getting their heads around the fact that women's bodies do not exist to satisfy men's desires 
"are you advocating for egg donation to be banned also?"
No, because the woman who is pregnant and taking on all the additional risks is doing so because she wants a child and not because someone else wants one. She's taking that risk for her own benefit and not for the benefit of someone else.