The only time in my life that I ever wanted things based on brand name and/or because it was what other people were wearing occurred just before I entered my teens.
Fortunately for my mother and grandmother, not to mention fortunately for me, it was a very short "phase" that burned briefly but brightly.
At the same time, I am glad that it happened, because I think it makes me better able to understand why people, even those whose teen years have long lain folded away in the memory box of Time, will be willing to spend more than many people - including themselves - earn in a month to acquire one single item!
As Pursegrrl points out, the adolescent years are always going to feature a certain amount of this, it is all part of the process of becoming a woman, and developing one's own style, transitioning from the attitude of trend-follower to trend-setter
And I believe that even those who still bear traces, or more than traces of it, well into adulthood will eventually find that it slips from them like a leaf that falls from a tree, and if I may be forgiven for waxing philosophical, in the circumstances that society finds itself today, for all the criticism that can be made, and with undeniable validity, of the practice, and considering the truly horrific and horrible things that the trend-followers and status-shoppers could be doing, their attachment to a particular brand name and/or style of fahsion and/or accessories does not seem so bad!