Well, generally, they tell everyone the price. In this case, they're only telling you the price, and that price might change tomorrow, or in 5 minutes, or if yo

Well, generally, they tell everyone the price. In this case, they're only telling you the price, and that price might change tomorrow, or in 5 minutes, or if you move 5 blocks to the south, or if the local commuter train gets delayed, or... By how much, for each input? Who knows. Hence, the concern about the lack of transparency.