"This may seem like an odd suggestion, but since this is the mustachian forums I have to throw it out there: could you just go bra-less?"
This is a matter of personal comfort. When I had smaller breasts, and was younger and not in a professional setting, I would frequently go braless. But I was certainly much more attention seeking at 21 than at 31. Now that I am older, have larger breasts, and work full time in a professional setting, I would not go braless in most public settings. At work, I don't want people in my office distracted by my boobs, and they move independently, and when they are larger, there is a lot of noticeable movement. So in that setting it is a question of people taking you seriously and not being the one at the office with visible nips or getting a rep as the free-boobing lady. Out and about in everyday life, it's not really fun being stared at by strangers. Straight men tend to stare without noticing it, and some don't care if they are noticed and are practically predatory, and some are actually predatory. I'm not saying that this behavior from some men is ok, and it would be great if we lived in a different world, but the fact is it is uncomfortable and at times downright creepy to be stared at. These are only the social/emotional comfort issues. Frankly, now and again I say f-it and put on a sweater or something heavy/baggy and go out to whereever without a bra. For active movement, it is actually physically painful to run/jump without a bra.
I have two nude (the color i find the most widely adaptive to all colors of shirts) bras that I like, I care for, and I wear them until they are dead. From a mustachian perspective, I think you can minimize the bras that you need, but for many of us they can't be eliminated without various, real discomforts.