Women competing in the ATP is not a thing. I don't know why you even bring it up. This is what you don't get. Sponsorship DOES matter. Ability to compete across genders doesn't. You've completely missed the commercial viability quotient. What you're worth on the market matters more than if you can beat X-player across genders. Or even within your gender. Tomas Berdych has had a lovely career, but he isn't worth half what Kei Nishikori is. Why? The market. Serena, Maria and even Venus are wildly more marketable than current or former #4's Ferrer or Wawrinka. Argue all you want with me about how well the men play tennis compared to men, or all the rest. It's window dressing. The answer is marketability, and there are solid women that have it. Li Na is going to have single-handedly changed the face of tennis is 10-15 years when all those kids in China who were inspired by her start turning pro. Mark my words. Ergo: equal pay.
Moxie you would know by now how flawed your logic has been, just about nobody here disagrees with you one way or another.... it's not personal, and it certainly isn't that 'it bothers guys that women get paid equally', or more ridiculously, that it's not our money.... you sure you know what you are talking about?
Prize money in any given to winners, depending on how much they win. You don't award Fed or Djoker more money than David Ferrer if they win the same event right? the commercial value of course would be reflected differently, via appearance fees and sponsorship. So simply put, prize money is given to the better players (because they win).
Now when it comes to prize money distribution between men and women in any individual event, should the event owner be allowed to allocate money where they see fit? that's the problem these days, they cannot do it because the current social disease (feminism) would disturb such rights, even when it's clear which side brings money for the tournament. You've been relying on single matches (like Serena's USO final) and think you can upsize an exception without limit, but seriously, who are you trying to fool?
Good example with Li Na, the chinese have been very smart with their tennis program. Their sport minister once revealed that they would prefer to train women because it's easier to produce GS winners. If they invest the same none and train the same number of men, they have little chance to produce a male champion.... it's simply tougher to achieve the same in ATP, so you can see why these communist countries (like China and Russia) have only really been successful producing female winners while the men have been nowhere near as successful. It's simply an opportunistic approach, funny you take it as example in your 'equal pay' bible.
Instead you mark my words, women are not as good as men in sports (not just now like you said), they have never been and they never will be. And they'll never be as good innovators, scientists, engineers, leaders etc; by and large. If you take the feminism crap out of your brain, you'll begin to acknowledge and appreciate the 'facts of life'.