You can find the Snoop Dogg G Pen in various stores and marketplaces online. However, you will not find them on Amazon because Amazon does not allow them to be sold. It may even be difficult to find them in stores, or they may be more expensive in stores.
Grenco Science sells the pen for $99.95 + Shipping
I have found a deal however for $32.95 shipped for the Snoop Dogg G Pen. Follow the link below for the deal: