#1
Hey my band and I have been using a line 6 75 watt guitar amp on clean for practicing our vocals for the last couple of years. It's sounded like shit but at least we could hear ourselves. Unfortunately (or fortunately) the amp has been taken back by it's owner and we now need a cheap method for vocals in practice. We have a couple Shure SM58s, so now all we need is a way to amplify the vocals. What do you guys think is the best method for around $300? I guess we could spend more but I'm not too fussy about the quality of vocals for practice (just has to be a step up from the guitar amp)

Info -
Edmonton AB Canada
Used/New
$300
Thrash Vocals

I've seen some powered speakers which seem to be a good method, but are they capable of handling more than one mic? We have 3 singers so it would be nice if we could all chime in during the practices.

Sorry if I haven't included everything, I'm pretty new to this area of audio equipment.
Gear:

Squier Strat
Epiphone Explorer
Agile AL-3100

No AMP
#4
Try to find a cheap used PA on craigslist. If you're lucky, you can pick one up for really really cheap. My dad got one (don't remember what brand, but it was definitely a cheap one) for $75 (with speakers).