Ever since Article 86 of the EEC was introduced, there has been persistent uncertainty related to the true meaning of what was to become Article 102 (a) TFEU, according to which it may be an abuse to directly impose unfair purchase or selling prices or other unfair trading conditions. In other words, it addresses the situation when a dominant undertaking is overcharging its trading partner for products sold, or, conversely, undercharging trading parties for products purchased. Although the antitrust effects of such mirror images are arguably different because the alleged abuse would take place higher or lower in the distribution chain and it may not manifest itself in the same way amongst end consumers when the results of the pricing behaviour inevitably trickle down through distribution chain. To simplify for the purpose of this Article, it is illustrative to focus on the situation when a dominant undertaking charges an excessive price. At the outset, the adjectives ‘unfair’ and ‘excessive’ says very little about where to draw a distinct line between high, but lawful, prices and those that are so high that they are unreasonably high or excessive and thereby unfair.