That's a tough one. It really needs just the right buyer for it. Unfortunately, it will be harder to sell without a transmission, especially since the original E-Maxx tranny is now essentially obsolete. On top of that, with so many other options for trucks these days, the G3R really doesn't stand out as much as it used to when conversions were far more scarce.
Well I have a stock e-maxx 3906 tranny I can include with it so maybe that will help out. From what I have found all of the parts are still available for the 3906 tranny (you can still build a new one). I figure with no outlook for a G4R anytime soon maybe someone around still wants a G3R? If it doesn't sell it will just be another one sitting on the shelf, no biggie.
To give you an idea i bought a G3R CF chassis as a complete roller from the Traxxas forum for $230US Plus shipping. This was without electrics.
I also bought the Aluminium G3R as a roller with a lehner motor, Quark ESC, JR ultra high torque servo, Custom made Center diff and motor mount, Spare chassis bottom plate and spare battery strap set for $650US shipped to Australia.
There is no need for it to become a shelf queen. put it on EBAY i am sure someone will buy it, you could sell it for parts, someone will definately buy the electrics.