They're going for about the same as Lessers based on gender. It's not so much that they aren't popular, there just aren't as many out there. Their potential hasn't fully been seen I believe. Look up the Opal Diamond. It's gorgeous.
There haven't been too many combos made yet either as far as I know. They are also a lightening gene and brighten anything they are combined with.
I'm surprised the price of a Russo isn't up there with Mystics and Phantoms considering they create similar morphs.
Snakes, Jeeps, Dragons, Nature, & Knives.. Makes my world go-round!