Keep looking. I just found a rescue with robos and have one coming next week (they're too far away from you unfortunately). I also don't think I'd be up to making a full level so have gone with cardboard round the insides to reduce the height
Cut up an amazon box and have 4" high cardboard round the inside. Works ok - only thing is means you can't take the top off without removing a lot of substrate first. I rarely take the top off anyway.
Try and find rodent rescues in your area on google. As Souffle says though, a rescue robo may not be easy to tame (or may never be tame) unlike one from a breeder.