Help me obtain some isolation!

I'm trying to do some recordings in the practice space my band uses. The problem is that other bands practice in the building, and I am afraid I will get some roaring electric guitar bleed in my overhead drum mics. The sound from the other bands isn't too bad normally, but I am still worried. I am using SM81's for the overheads. One of the problems is I don't think I can physically attach anything to the walls of the room. Is there some sort of baffle I can construct to help this? Will hanging blankets over mic stands around the kit do any good? Any ideas? I was thinking of possibly making a sort of collapsable room, 6 Feet wide, 7 feet long and eight feet high, using 2x4's and plywood to make the frame, then filling it with ultratouch insulation, and covering it with another sheet of plywood. I would then hinge the 4 walls together so that when not in use, It could "unfold" and rest against the walls of my practice space. I would hinge the "ceiling" to the rear wall of the booth, so that when I set up the booth, I can flip it up and rest it on top of the opposite wall. I would then treat the inside with Auralex or something. But I would also have to throw a window in the front wall, and I am very unsure about how to soundproof that. I figure this could be done for under 500$, but does anyone think this would actually work/help? Thanks, Tim

No, it would not work. The walls would move and the hinged ceiling would swing down hitting the drummer on the head rendering him or her a vegetable. And no body likes vegetables!

Depending on how bad the noise is, maybe you could buy one of those fully enclosed drum booths with plexiglass walls? They don't isolate totally, of course, but it might be enough. But I think it would cost just a little more than US$ 500!