I saw lots of red ones, and bought them now and then thinking they'd be semi-abundant but they dried up fast. When the 3-packs clearanced they dried up too, though I always felt that BD 3-pack shoulda been one SBD (just re-release the Saga one if you ask me) and pack in 2 red BD's... That would've helped a lot.
I got some, just not as many as I'd like having. A 4-pack of BD's of a single color would go a long way I think, as a steady seller. I don't think it'd fly as fast as the Clones, but I bet it would do well at the right price with the right quality behind it (IE: won't fall over under their own weight like the Saga white droids did).