There is nothing grammatically wrong with the sentence, but it doesn't make very much sense. I think what you mean is "I wouldn't go out with her even if you paid me." The sentence as written implies that you are currently being paid not to go out with her, but that you would continue to not go out with her even if you stopped being paid.

If I understand what you are trying to say, you would say . . . "I wouldn't go out with her even if you paid me."