There are a ton on the market right now . . .

I have a few out there (adult / sub adult)
Vital Exotics has plenty of fresh hatch
Jason Reed has some higher end stuff going at an excellent price

Fauna Classifieds has some listed, Kingnsnake doesn't though it's mainly people listing on facebook since retics are pretty specialized. Join Retic Classifieds, and the Retic Market pages on facebook. That's your best place to start.