Are they common? Hmm... well, yes. They are not rare, as Petsmart sells a lot of A. coronata along with other petstores. Certian speciese of Acanthosaura can be rather diffucult to find, but MHDs as a whole are fairly common.

There are still a lot of people who have never heard of mountain horned dragons. But it definatly isn't a rare dragon if that is what you are thinking.

I haven't really tried my hand at incubating MHD eggs. If you noticed, I just asked this question on a seperate message.

I appears that they should be kept at a normal room temperature and should handle large temperature variation
-----
Ryan