My room size is about 12'x15' with about 8' ceilings. I'm on the top floor of a two family home with the landlord occupying the first floor. So there is a small amount of concern for overpowering sound, but they are fairly easygoing and I just would have to make sure I don't blast the volume after midnight.That said, a sub is not something I think I can realistiaclly take full advantage of, but please correct me if I'm wrong.
As far as budget is concerned, it's tough to say. I'm willing to make an investment in whatever I purchase, even if it means I must slowly build the components over a year. So for example, if using the KSB's won't match very well with any other fronts I purchase, I could consider new fronts and center altogether, and maybe use the KSB's as rears to tide me over until I figure out surround options? The short answer to your question is, over the next 6 months, I could see myself shelling out $600-$1,000. The combination and order of purchase is what I'm really grappling with.