This just made me laugh.
Mr. Red was advertising Titanium Ore at 400g/stack, if I remember correctly. Mr. Blue was undercutting that forcing Mr. Red to drop his price. He finally got pissed off so Mr. Blue offered to sell his ore to Mr. Red. LMAO!!!
By the way, I prospected my 6.5 stacks of ore and got 6 epic gems!