Amazing what we keep hold of isnt it?! i only have 3 that fit now. There are plenty of bra charities you can donate good condition ones to. Google for them - I think Oxfam are also having a bra appeal at the moment. After 8 years of pregnancies, breast feeding and weight gain/loss I donated 30 bras a year ago!
I was about to go bra shopping thinking I didn't have enough so I tipped out my underwear drawer and had a check. Well I had over 20! 10 of which didn't fit well or were ugly looking. Also got rid of any nickers that either didn't make me feel/look fabulous or had a specific job to do.