Greybros got it. Basically, this is a big props pack that as a bonus contains a version of WorldZ. Twelve bucks for eight props? Thats 1.50 a prop, bargain by any standards, so it's not really a case of buying WorldZ all over again. This is a more specialised product than WorldZ itself, and as such, will not have as wide an appeal. And as Greybro points out, had we released this as aprops pack, the price would have been higher.