and as for the dresses, most of them are given to the celebrities by the designers. It's advertising for them, because people see a chanel dress that's beautiful, and therefore want something that's Chanel. Rich people buy the ready to wear clothing (because NO ONE can afford couture, less than 200 people in the world actually), middle class buys the accessories, such as bags and belts and sunglasses, and us poor people buy the smallest bottle of perfume haha. I agree that there's better things to spend money on, but I admire the world of couture, as it is the only thing keeping some sewing and clothing traditions alive today. Most actual couture is almost all hand sewn.
Sorry for the rant. Argh crazy fashion student here. :/