Now…let’s say order volume in NY is 10 orders, and volume in PA is 2 orders. Taking the average of the two averages would give us $75 as the overall average cost. (($100+$50 = $150)/2) = $75 However, if we take volume into account, as we should, the average is $91.67.10 NY orders at $100 = $1,000 + 2 PA orders at $50 = $100, for a total cost of $1,100, divided by all 12 orders = $91.67.hese numbers rarely match because taking an average of averages is wrong. The reason an average of averages is wrong is that it doesn’t take into account how many units went into each average. For example: Let’s say we only have orders in 2 states, New York and Pennsylvania.