First, I'll say there's absolutely zero (zilch, nada) reason for a real CAT tourniquet to cost as much as it does. We mass produce far more complicated things for far cheaper -- it costs as much as it does because that's what the market will bear, especially when a lot of your customers are Government (local, state, federal)

Tourniquets aren't rocket science, nor do patients have to scream to have them on correctly -- they need to be tight enough to occlude the artery and stop the bleeding, which you can simulate in practice by tightening them up enough that you no longer feel a distal pulse. It's not particularly comfortable but for most of the population certainly not unbearable.

I only use the real CATs in my kits, and plan to even if it's something I have to acquire over time due to cost. However, in all likelihood, the generic tourniquet listed will work just fine -- the real danger with improvised tourniquets is using something too thin which may cause lasting tissue damage. As a CAT knockoff, we know the width (which matches that of the CAT) is sufficient for safe use, so really as long as the thing doesn't break, there's no reason it shouldn't work. That boils down to their QC, consistency, the strength of the plastic buckles, windlass, susceptibility to UV or other environmental damage, etc. That's a call you'll have to make after an assessment of your needs, risks and what you can afford.