What Moorea said.
The Powerizers aren't a prioritary thing with the Buzz Pro. Mike at NotCigs was just getting a bunch of questions about which batts lasted the longest so he bought some testing equipment and tested a butt-load of different batteries and the Powerizers came out on top. People didn't know where to get them so he started carrying them per peoples request.
The fact that NotCigs carries Powerizers isn't market manipulation, it's really good customer service. You can use any 3.6 or 3.7 volt 16340 size battery in the Buzz Pro.