Title IX says that "No person in the United States shall, on the basis of sex, be excluded from participation in, be denied the benefits of, or be subjected to discrimination under any education program or activity receiving Federal financial assistance." (There are exceptions that aren't relevant here). That prohibition doesn't necessarily go away if that person is being paid. Certainly nothing in Title IX says so. It may be that, even with respect to compensated individuals, Title IX imposes obligations on educational institutions that go beyond those imposed by Title VII. I'm not saying that's true -- only that the question is closer than some of you are suggesting.