Room treatments can get expensive. But, it is the only way for us with less than perfect rooms to get the best sound. We all know our rooms are a MAJOR contributor to the sound we hear right!? Now, how many are willing to spend money on room treatments? Not many. Want proof? Search the systems here on Audigon and take a look at the pictures. If some would spend less than the price of one of their cables on room treatments, or even some thought and time on placement, dramatic improvements could be made.
The good news is that you can have some fun, learn something and it will probably cost less than your power cord. If you understand some math, basic room acoustics and material properties, DIY room treatment projects can often get you a significat percentage of a mainstream products effectivness. If you don't understand that stuff but want to, search and read the web. I actually took a class on this stuff for my undergraduate engineering degree years ago...and kept the book.
There are a couple free room software analyzers that will give you a good starting point for set up, just do a search on the web. Next get a test CD and an SPL meter then listen and take notes and measurements. Find and understand what your problem areas are first, then attack them one by one as the effects may stack up. Use your ears as the final test.
Local fabric stores (foams, fabrics, stuffing, batting) and hardware stores (insulation, frame materials, required tools) are gold mines for this stuff. Ever notice how the insulation isle at Home Depot is really quiet?
Good luck.