My friend won't stop copying me!!!!___?

Ok, I have this friend and she won't stop "copying" me. How can I tell her to stop? We've been friends for say 3-4 years now and I just noticed this "copying" had start about 2 months ago. Like if I shop at Body Central (my fav. store) she goes and buys the SAME EXACT clothing as I do. And don't tell me it's that flattery thing 'cause it ain't that! She won't buy EVEYTHING I get 'cause...how do I say this nicely...my family is really wealthy and I can afford $900 worth of clothes at a time and she can only afford about $200. So, she'll get some of the clothes I get, but it SUCKS 'cause then we'll wear them on the same days sometimes and how do I tell her to get her own style? My style is like a preppy/sweet/fun look and her's is gothic/punk. And she decieded she wanted to look more of a girl so..she's now taking my look. SHE SHOULD HAVE HER OWN PERSONAL STYLE!!!! How can I tell her to stop copying MY style and get her own? Same w/ perfume. I told her I was getting "Princess" by