I wouldn't go cheap on a boom if I were you. If your stand topples and you break a flash tube (or worse), you just spent more to fix or replace your equipment than you would have if you just bought a decent stand in the first place. Figure out how much weight you need to support and go from there. You absolutely need counter-weights at maximum extension, so consider that as well.
The Bogen/Manfrotto 3397 (chrome) or 3397B (black) is a very decent stand, is rated for ~5 lbs. at full extension, and includes a counter-weight bag. It is fine for a head with a grid or snoot. New, they run about ~$150.
If you want to put something like a large softbox on the head, then you'll need something more robust for full extension. In that case, I'd recommend something like an Avenger 470 or 475. They'll hold ~12 lbs. at full extension with counter-weight and run ~$200.
People who do stupid things with dangerous substances often die! -me