re: Big green egg charcoal

Royal oak makes BGE charcoal for what it's worth. The bag even says, "Manufactured exclusively for the Big Green Egg Co., Royal Oak".

RO 10 lb bag is 6+ bucks at Walmart. The Walmart is a bit smaller pieces. For cooking a steak or pizza at high heat or other such applications the RO gets a lot hotter, due to the increased surface area of the smaller pieces.
I've never seen enough difference to justify the double cost.