My band is starting to get more serious. We're about a few weeks from getting an EP recorded, realistically. Being a vocalist, I've been using a guitar amp. Yes I know ghetto, sketchy, etc. it sounds fine when on the proper settings, but it gets feedback like a mofo. I need a PA or a pair of PA's I can use for practice. They don't need to be anything amazing. Just loud enough to hear over the drums. It's a metal band, if that makes a difference. Not looking to spend a shit ton either. Give me some ideas please! Much appreciated.

QSC K Series. K10's are best bang for buck.

http://www.sweetwater.com/store/detail/K10

Not sure if $750 is too much but I think if you spend $400ish you'll ust spend $400 to not hear yourself.

You could try a Peavy SP12M and try and find a used power amp sufficient to drive. Excellent loud speaker for $499 but the QSC is self powered. If you're desperate, you can play your mic straight into the QSC and it'll work.

http://www.zzounds.com/item--PEVSP12M

Thanks

You should get a high-medium quality one instead of a pair or low quality. (for the same price i mean, you'll see the difference)

I suggest you take a look at the Eon PA speakers from JBL.
I play myself in a metal band and when we started, my singer bought a used 400w JBL old generation PA speaker (that are now Eon speakers) and it is still working perfectly fine to this day (that was 5 years ago).
You could always buy one Eon 515 now and wait a year to buy another one