Wowzah!!! She's a beauty!! I've never seen one like that.
It's just a low grade (most likely B) CBS. They won't have both red and black, that one is definitely a black. $30 seems like a lot to pay for her!
I agree that $30 for a single adult is steep, but an adult female plus 9 babies for $30 is a deal, even if the coloration isn't very good... in a few months that's worth a lot more. patience.
ideally, you'd want an adult male asap as well...