Yes it gets expensive fast .
If you want good AND loud. Really expensive!
My point is more along the lines of, we all take alot of time to pick the guitars we like,the amps we like and so on.
Do the research,take the time to purchase your PA equipment the same way because its what puts you out there to your audience.
Powered speakers is THE way to go. Lots of bang for your buck and they last. A good mixer is a must. A good vocal mic for yourself to DIE FOR! Everything else you can kinda dink around with alittle.
Budgets for this stuff are always on the light side but with a little research and planning you can make your PA bucks go along way!