chean: FWIW, Crossworlds is a standalone expansion that apparently contains the original Armored Princess campaign as well as an expanded version of it, so it seems debatable whether picking up AP itself is useful/needed if you have Crossworlds.
Grargar: Then an important question arises; why are they still selling the original Armored Princess and why are they selling it more expensively?
That's a good question; but looking around on other sites it seems there may be two versions of Crossworlds as well -- one expansion that requires AP, and one that's standalone and effectively supersedes it. So if Amazon are only selling the non-standalone version, I guess it makes sense to sell AP still. o_O
cmdr_flashheart: That's an interesting list. Would be nice if someone who has the games on steam could confirm.
I have them, but only installed Crossworlds today, not yet the others, so can't say for sure right now... but there appears to be no activation or similar needed for it at least (just tried starting a new game to see).