I have like 8 or 9 every day bras for work, and I have 4 or 5 for not work. Work is outdoors and dirty and sweaty and sticky so my everyday bras are the ones that are comfortable, easy-care, wireless, and not expensive. I have fair quality everyday bras, and decent quality not-work bras.
I probably don't need that many bras, but i do try and keep bras for different colored tops so that there's not a glaring white bra under my semi-sweet grey tunic tank.