the free thing you are talking about is not a human modelling program, its just a free render engine, there is no rigging, no moddeling.. well you might be able to get a basic shape with something using D-form.
the models you buy are extra, each run about 120 thousand poly and are unusable for games.
Daz does however sell Hexagon wich is a decent little modelling program, last week it was on sale for 10.99 , if you check for special offers you can get carrara or hex or even bryce for decent pricing.