Again, as I stated in my post above, your statement is true if someone is actively farming a mat using time that COULD have been used to do something that would make as much or more money, like running dailies. However, if they are already doing something productive to accomplish something else and happen to get the mats they need/want while doing this other task, then no it doesn't cost them as much as buying from the AH, from a money or time stand point.