Animewrote a review of Cutter 26in Premium MTB Tubes - 4 Pack on December 3, 2012
These are Presta Valve, Merrick brand tubes sold as Cutter, made in China.
Not the highest quality, but they do seem to be what you'd put on a real bike rather than something from walmart. The rubber is thinner and so lighter, but not as thin as a lightweight race tube.
If they hold air I don't think you could ask for more given the price. Even at 8.95 these are a deal, even more so if your LBS wants $8-12 per tube.
The other interesting thing is the tubes supposedly have a lifetime warranty. The label says "Lifetime Warranty: If this thing sucks, send it back at any time." Not sure if you get anything back or just get to send it back. Their site is down and the cached version says it's getting a facelift in 2012 and will be back strong.
My guess is they are out of business and the reason for the pricing on the tubes is because they're stock that Realcyclist got stuck with and just wants to get rid of. So the lifetime warranty is probably worthless. Not that it matters, I'd never expect a warranty on something like a tube. If it holds air until something sharp gets stuck in it, and a patch will stick to it, I'm satisfied.