Level creation is the key of Littlebigplanet success,there's not enough major new functionality in level creator on LBP2 and 3 to justify buying them.
PS4 - over 100 millions let's say 120m
Xbox One - 70m
Wii U - 25m
Vita - 15m if it will not get Final Fantasy Kingdoms Heart and Monster Hunter 20m otherwise
3DS - 80m