I'd imagine that the reason the addon is slightly more expensive from VStep is that they/Lighthouse set the retail reccommended price which retailers (Amazon, Play etc) can discount it if they choose. VStep/Lighthouse cannot as it would be seen as unfair to them. However the VStep version is a download, sans packaging so you would think they could make it cheaper due to that, especially since they will make about 3 to 4 times more profit on this by selling direct and not through normal retail channels with all of the middle men that involves (distribution,transportation, retailers cut etc)