Is almond butter rare?

Yeah, it's pretty common now. It's like peanut butter so found usually by the peanut butter section. Some Wholefoods has a peanut butter grinder, if they have fresh grind peanut butter, some of them would have fresh grind almond butter machines as well (same area).

Also check for it at a health or specialty food store if you cannot find it at your grocery store.

Available broadly now. At places like whole foods, you can fresh grind your own, which is the way to go in my opinion.

It is easy to make your own almond butter. I do it all the time in my food processor. Here is a video showing you how to do it. http://food52.com/blog/2228-how-to-make-almond-meal-and-butter

No, I have purchased it at the local supermarket as well as Trader Joes.