i mean 400$ for some cloth, foam, and wood..... seems like about 50$ of materials or so....... If the materials cost 50$, then even with a small demand, i would expect the price to "maybe" be 150-200$.... but 400?!?!?!?
Actually foam = bad...
The "best" stuff is generally considered to be Owens Corning OC703 and OC705 rigid insulation. There are other products with similar acoustical ratings. Some people go with mineral wool which isn't as stiff and needs more bracing. Either of these options will put you into the couple $100 bill range pretty quick.
You can save a little more with some superchunk traps like Randy (Mr Quack) did, but use the denim insulation. It will obviously need quite a bit of support.
To save even more, there are a couple of guys in the Acoustical Treatments thread at AVS that say that the cheap ol' pink fluffy insulation works well too, if the trap is designed right.
But foam is crap. The places that sell the foam pieces in different colors and such have been ripped apart with their own technical data and independent testing over at AVS.
I better figure out what I want to do in my theater pretty quick. Carpet just got installed today...
