I don't know the MFG date since I no longer have the box, but I purchased/registered the Pro new in the beginning of Oct 2015. It has been in use from Oct 2015 to now.
Last update before resorting to eBay:
Radion G3 (non pro). Purchased 11/2015. Power supply not original. Power supply was assembled in 2013. - $480.
Radion G3 Pro. Purchased 11/2015. - $580
Radion G3 (non pro). Purchased 11/2015. Power supply not original. Power supply was assembled in 2013. - $425.
Radion G3 Pro. Purchased 11/2015. - $525