"If it seems too good to be true, it probably is..."
Okay, so it's using approximately the same materials as a 2BC extinguisher, but spraying them 4 times longer (and about half the quantity). It doesn't have an ABC rating, so it's hard to compare. Hmmm...

If you're just having it for a portable thing, yeah, sounds nice, but if you're doing pro shows where a fire marshal is gonna be looking at your extinguishers, etc., then, no probably not. Because when it comes right down to it, safety equipment is the domain of fire suppression, and THEY say what's good and what isn't.

www.firstalert.com/fire_ext..._item.php
Those can be had for about $25 or so bucks. They use sodium bicarbonate, so they don't suck too hard if you get hosed down with one.
Class K extinguishers are generally 10-14 bucks, and will not pass a FM inspection for a professional show, but can take care of smaller fires no problem.

how cheap do we need to be?