I am new here, but thought this might be a good place to poke my head in.
I just recently finished building a studio from the ground up...took a bit over three years. In the process I did quite a bit of research in the acoustic treatment realm. I suggest you consider constructing your own absorbers using 3" rigid fiberglass and/or mineral wool mounted on 2"x"2 or 2"x4" wood frames, covered with fabric of your choice. It is much less expensive and much more efficient than alot of high end foam products. Egg crates can help slightly to contain high end reflections but do nothing to help control low end, a critical oversight in most home recording environments.
Check out
www.musicplayer.com for some great info and insight.