If you get the Deluxe Shift Kit, you not only get the White Industries Freewheel but you also get all of the useful tools to maintain your bike; which works out to be a significant cost saving if having to individually purchase these items.
The other issue is that of shipping cost, because once you factor in the $10 or more of shipping from White Industries (if they would even sell the freewheel to you) there would be no cost saving.
The way things are, SickBikeParts is becoming a one-stop-shop for just about everything. If only they could redesign and make improvements to the Nuvinci Hub for motorized bicycle use.
Hopefully they are getting a move-on with their replica GT LTS heavy wall steel frame.