According to Sinclair himself, the £69.95 price was chosen after applying the "experience curve" developed by the Boston Consulting Group. Sinclair's prior experience in the calculator market had highlighted the fact that a product will be more profitable selling at (for instance) twice the manufactured cost than at three times. He could have launched the ZX81 at a higher price, marketing it in a more traditional way as a premium product, but chose not to. In effect, he used the lower price to establish an unassailable lead before the competition moved in.