I agree, you can live without a center, but you're missing out without a sub. If the 503 is out of your budget, go for the 502. I think it is pretty much the same receiver in the Onkyo 780 system I installed for a customer recently. Of that $500 system, I think the receiver was about $400 of it, because it was actually pretty decent, and if it is similar or the same as the 502, it should work fine for you (as long as you don't have a big room).