If you're not concerned about containing a large percentage of particulate coming off of your printer, you can opt for my low cost enclosure solution.
The curtain enclosure:
The curtains each measure 28" x 15.5" and are cut from pleather that I had hanging around the house. I would guess that most fabric you have hanging around would work similarly enough.
The fabric is inserted in the small clamp on the back of the curtain clip and the clip is simply slid on the plate at the edge of the build area.
Here's the clip model:
Curtain Enclosure
Re: Curtain Enclosure
I like it! It's a lot cleaner than my canvas-and-binder-clips version. 
g.

g.
Delta Power!
Defeat the Cartesian Agenda!
http://www.f15sim.com - 80-0007, The only one of its kind.
http://geneb.simpits.org - Technical and Simulator Projects
Defeat the Cartesian Agenda!
http://www.f15sim.com - 80-0007, The only one of its kind.
http://geneb.simpits.org - Technical and Simulator Projects