They droped in the bank area. Bonus as I was working on faction. The gems cost me 260 total in the bazaar this same night also. I agree that they are not good, but they don't suck either.
If I stumble upon the gems, I'll roll for them, if I stumble upon the sleeves, I'll roll for them, but I won't go out of my way to get these. This sleeve is not so much of an improvement over "normal| equipment.