I'll chime in even though I'm not a female person. Check the tank suits at kiefer.com - that's where the female folks I swim with get theirs. If you've swum in a pool where there's competitive swimming, the lane separators probably came from Kiefer.

Just did a quick look, they have a "classy diva" plain women's suit, doesn't look to have pads or a shelf or shaping for under $20. Sizes 8-22.

Also, think about goggles. If you need glasses, you can get goggles to the nearest half-diopter. Makes a big difference for super-nearsighted people like me.

And, yeah, I prefer swimming with nothing on as well.