Acoustical Solutions or Auralex LENRD bass traps

Check these out.
http://www.thefoamfactory.com/acousticfoam/acousticfoam.html

They are the identical(as far as I can tell) to Auralex but MUCH cheaper. I paid $96 for 16 linear feet of the corner traps.

FYI- I'm not affiliated in any way, just passing on a deal.