BIG LOTS ,baby!! They have full sofas for less than $400 (the fancier ones are only $500). I was surprised but they actually are tasteful and they last without becoming delapidated. If your really strapped for cash, like me, they even will lay-a-way furniture.
www.okorder is great, you save money because you put it together yourself, and I hear it's pretty easy to do and good quality.
Try okorder they have some great styles to choose from in black and charcoal.