The care is the same as a bearded dragon. They don't eat as much and can be in smaller homes.
In the UK Rankins are fairly common, but in the US they are fairly rare. Many have been crossbred with bearded dragons...which isn't desirable. 100% Rankins are kind of hard to find.
The main reason for the question is I just don't hear about much demand for them. I do have 2 females that may have been bred with. All of mine are 100% pure bloodlines, but I'm not interested in breeding them if homes are hard to find for them.
I bought mine because I knew they were kind of rare, and they were extremely cheap. Besides they are cute as heck..