This depends on the music I'm listening to. Sometimes I set it really high and others really low. But I'll have to start watching what number I actually put it on.
Well how do you like the Pioneers? I remember getting some a long time ago that were really cheap. Like you I was in college with not a lot of money to through around to new speakers. They did the trick as long as you didn't try to go too loud. Just enough to roll around town in and have music playing.
I get my speakers from www.audio-equipment-speakers.com but they are more professional speakers than general home speakers. As for receivers and such I just check out the exact model I want and shop around on the internet to find the best price.
Well you would be hardpressed to come up with a decent system with only a $600 budget but it can be done. Have you thought about just starting out with a decent receiver and some fronts then adding as you go? That way you know your not cutting any corners with quality just b/c of price. I would check out online to find some of the best prices...just don't go down to best buy and start charging.