In your example, I suppose I lost the PGA Masters tournament, because I didn't enter.
As in I suppose I lost money on not selling the NA26, because I didn't have it.
1)You would've lost the tournament anyway.
2) You didn't have access to the book, but DTA did, and his (or whoever's) play resulted in no sale. Hence that's probably over 1k he could have in his pocket that isn't there.
Apples and oranges, but I think you know that and are just trying to be difficult.
Your position makes no sense. By your logic if a book doesn't sell, then a consigner losses money. That's absurd. How can you lose money, you never had in the first place. I can see not gaining any money, but not losing money.
It is a loss. To be specific it is considered an opportunity loss. Think of it like this: The manager of a bookstore orders 100 copies of the new Harry Potter book, but 200 people show up the first day to buy copies. The bookstore has an opportunity loss of 100 copies ($1700 or so in sales) because those customers would have purchased them if the store owner had ordered them.