Hi
Since starting cycling this spring, I too have lost a dress size. I have not replaced tons of stuff, but I have noticed some of my bras are getting too loose.

If you have some time to spare and don't mind hunting through racks, TJ Maxx and Marshalls sometimes yield fantastic lingerie finds. I have become a bra snob and love some of the nicer brands like Wacoal, Chantelle, Natori, etc.
I find them sometimes at TJ Maxx and Marshalls. I frequently see the odd sizes - like small band/big cup, or AA. I make it a rule to not pay more than $15 for a bra (except sports bra), and usually can find many of these brands for $12.99-$14.99.

As for sports bras, I too hate the compression bras. I have a few Lily of France bras that aren't too bad that come in band/cup sizes as opposed to small, medium, large.

I saw a Craft of Sweden cycling specific sports bra that looked promising online - supposed to wick and offer some wind protection over sensitive areas. Anyone tried that?