I see your point, I guess its all in how you do your accounting. One way of looking at it is the initial $7 dollars is already sunk costs, and quite literally h

I see your point, I guess its all in how you do your accounting. One way of looking at it is the initial $7 dollars is already sunk costs, and quite literally he probably was using the $7 dollars from Shirt A's sale to purchase Shirt B. I mean he didn't really literally take the $7 dollars from the sale of Shirt A to buy Shirt A so I can see why he thought that way. Does it make sense to run a business with that mindset i don't know...