Louis Vuitton prices their Pret-A-Porter in accordance with exclusivity rather than quality or craftsmanship.
Their logo is so ubiquitous (bags, shoes, luggage, etc) and it is so accessible that to control their image as the ultimate in luxury goods, they price their Pret-A-Porter accordingly. It is about maintaining a certain degree of exclusivity in the face of the globalized world where there is a Louis Vuitton store in almost every major city.