Photo credit: Ahmed Qadri via RM Sothebys That's right, this 2015 Mercedes-Benz G63 AMG 6x6 could be yours, if the price is right. It combines the G63's engine, with 6x6 portal axles, a pick-up version of the G-Class body, and a luxurious interior. This six-wheel drive vehicle is powered by a twin-turbocharged 5.5L V8 generating 536-hp and 561-lb-ft of torque, mated to a 7G-tronic seven-speed automatic transmission. Unlike the standard model, this one has five electronic differential locks…