i hear you!
been having probelms being an 8 my whole life.
from an F cup to a G (when BFing) and now an E

BUt i have to do that very thing, buy a cup that fits (usually 12DD) and have it altered.
I rarely spend under $100 per bra.
Evn used to do testing fro triumph when they were making an effort to fit girls of different shapes. but they bras were still around $80 ea