Once you purchase a Construct 2 Personal License, you will be able to export to cocoonjs and other exporters.
In order to put a game on the android market or the apple app store, or windows 8 you will need to pay for the developer license from each of those stores respectively. that's separate from construct 2.
I'm not sure about facebook, but i don't think they have a cost associated with them, i could be wrong.