for that money, you are better off buying separately. A used active 12"-15" full range speaker (alto are great speakers for the price), a 12-15" subwoofer (you need only one for starters) and a mixer should come under $1500. I would get a nice mixer though, digital or analog, 16 channel is nice for future proofing a band. Though we're maxed out already, (kick and snare), 2 elec guitars, 2 acoustic guitar, bass and 5 vocals.
Do you have guitar/bass amps?
This is what our band has done, we sound pretty good and def loud enough (though we use monitors/instrument amps which contribute to the volume) for small/med gigs. Mostly vocals and drums are going through the PA and instruments are going through in the background since we have amps. We are looking at sub-woofers, but honestly not in a big rush since we already sound good... though we do have a dedicated sound guy.