Idk how much they cost, I'm a guy and I don't ever plan on wearing a bikini xDD (Maybe as a prank tho lol).
But in all seriousness, I don't like bikinis for several reasons; For one, it might tempt would-be rapists. Now, I don't think that a rapist is excused AT ALL by saying "oh I was tempted by her bikini" because that's stupid, but honestly, why tempt fate? (especially with the pervs we have nowadays). Reason two coincides with that; girls always say it's sexist for men to stare at their boobs or butt etc. but yet they still put it on full display in public?! It's not logical. And again, how are you going to tell a guy it's wrong and sexist to stare like that then wear basically three napkins on your body? It's all very hypocritical- especially the prices xD I bet they do cost tons of money, and for nothing! XD
And also, what's to say a woman can't wear a bra and panties when she goes to walmart? Or a man a speedo?