My theory of prostitution and gender role reversal (thoughts?)

I was discussing my "theory" with a friend recently, and he seems to agree with me for the most part. It's not meant to be misogynistic in any way. I wanted find out if/how gender roles would be different if prostitution was legalized in the United States. Let me know what you think. (I realize it's oversimplified, but I think it must hold some truth. Also, I make a lot of assumptions, which by definition may not be entirely true.)

1.) Traditionally, men and women have had equal "need" for each other (women need men for financial security; men need women for sex)

2.) Today, earning power among men and women is roughly equal, so men have more "need" for women than women for men.

3.) The chief reason men seek relationships is sex; the chief reason women seek relationships is emotional support, raising of child(ren), etc. (Sex may be important to women, but not to the extent that it is for men.)

4.) Women are "needed" more and have greater power; thus, they control the sex. Men must do more work to obtain what they want.

5.) Prostitution greatly increases the availability and ease of sex, and a competitive market would ensure certain incentives (lower prices, no-obligation guarantees for pregnancy, STD tests, etc.). Thus, it becomes a more attractive route for the man's needs.

6.) Men would seek out fewer relationships, and the men who DO seek relationships would become rare, and thus would all of a sudden have much greater power.

7.) Gender roles would reverse, leading women to perform the roles men once did (i.e. asking out guys on dates, proposing, etc.)

I'm sure you guys can destroy this theory, but hey, just brainstorming.