Wow. I bought the keyboard alone a couple years ago from Apple for $100. Works great with garage band.
For those who are asking about compatibility with software - it's a USB keyboard, not a synth (though the keyaction is like a synth - very springy unweighted - not a piano). It works for me on a Mac with anything I've used with it, but I've not tried it with my older Performer rig (which is all midi based - this keyboard is USB). Still, I'd be surprised if there were an issue.
Like all controllers with limited keyboards, you have to press an octave up/down key to access the usual piano range. If you sequence this is only a minor annoyance. For performance, particularly two handed performance, you really need a 76 key controller minimum, and of course you need the moolah to pay for it.
For learning - most learning is less about action and more about scales, notes, etc. So I think this would be fine for young kids just learning, but after getting through the first couple grades of piano training, they'll need a wider keyboard, again 76 keys is going to be enough for most piano works. When you think they might become a concert pianist, then you can spring for the $50K steinway, or at least an 88 key hammer action controller :-). (I had both a piano and old Thomas theatre organ growing up - the organ had similarly unweighted keys, and I never had any problems playing either. I'm not a concert pianist, but I did go through 6 grades of piano lessons spread over 8 years (well we moved), along with about 5 years of trumpet).
