I was thinking of purchasing this software as a learning tool and to play with my daughters. Since my real board got lost in the mail it might be a while before the claim is finished and I can order again.

Is this a decent buy? or are there other comparable programs out there?

Thanks in advance for any advice.

I have champion go on my android phone, which I think is the mobile equivalent of crazy stone, and I like it for quick games, it's quite strong on small boards, and ok on larger ones (probably 5 kyu or so on my phone, it plays fast).

There are some free go programs you might check out:

http://fuego.sourceforge.net/

http://pachi.or.cz/

They are a little weaker than champion go, but they do OK and they're free

One thing you might be interested in: there are regular bot-only tournaments of various board sizes and time limits, sometimes crazy stone enters (as well as other commercial software like Zen):

http://www.weddslist.com/kgs/past/index.html

It's rather strong on full boards. As in well into the single digit kyu (KGS) range on its weakest setting. On small boards it's a very tough opponent. If you're starting out then it's probably a lot stronger than you need right now. As a teaching tool for a kid I'd be wary because unless they're of single digit kyu strength they'll be taking a lot of handicap stones and losing a lot even when you tune the AI down a lot.

(Opinion based on the weaker 2012 version of the software)