I am a F/G cup, and of a pendulous (aka sagging) bust profile

I HAVE found bras that are supportive, comfortable, don't leave me sagging OR uniboobed, and under $50 (I'm pretty sure they were under $40 in fact). I very very highly recommend
www.birthandbaby.com they have a huge selection (including bravado, not to mention every other brand I've ever heard of plus a bunch I hadn't!), but if you call them and tell them that you're looking for, plus your size, they can help you find a bra(s) that will work well for you. I actually spent 30 min on the phone with her this morning, told her my size (they have excellent measuring directions if you're unsure), and then told her what features I was looking for--no wires, no uniboob, etc etc--and she helped me find 4 different bras that met my criteria AND were in my size AND were in stock (they had a couple more that were backordered and she said I could order them and they'd call when they come in and if I still want them then they will send them, if not then no worries they don't charge for that). They have a very generous return/exchange policy too, so if somehow it doesn't work for you it's easy to get something else.
I have just been SO impressed with them. They were super helpful for me 3yrs ago the first time I was buying nursing bras, but after 3yrs of almost constant use those bras are starting to wear so I decided to indulge in a new one and talking with them was a very positive experience yet again.