Question for the OP: how much extra are you willing to pay for another rigging system and rigging tools?  IIRC the ProPack add on for Poser 4 was somewhere in the $299 to $350 range back in 2001. 

DAZ hasn't gotten around to telling potential buyers just how much their Content Creation Tools are going to cost.  Or the final cost of their Pro version of DS. 

Right now DS4 and Genesis is limited.  You can pose but you can't rig or do anything else.  If that's all you want for Poser then it probably wouldn't add much to cost.  If you want the functionality you are used to in Poser (especially rigging and creating your own custom cr2's) be prepared for a much higher cost.