Takeover Target, page-18

Coopec, the historical sunk costs are irrelevant and have little bearing on what an asset is worth. If you spend $100m on an exploration well, that doesn't meant you are going to get $100m for the permit when you try and sell it. It's only worth what the market is willing to pay.

Clearly the gas assets TAP are trying to flog are not worth as much in the eyes of the market as they are in the eyes of management, they would of found a buyer by now if that was the case.