Here are some other options you may want to consider that may be more cost effective in the long-run (considering the length of this I didn't just want to tack it on to my original response):
1) Get pieces that can be worn multiple ways,
This website shows a hi-lo skirt styled three different ways as a skirt, worn as a top and worn as a dress: http://www.fastfoodandfastfashion.com/2 … skirt.html
This one shows different ways to style a button up shirt: http://myclosetinsketches.com/2012/12/1 … button-up/
This image shoes how flats can be dressed up just by tying a ribbon around your foot: http://tinywhitedaisies.tumblr.com/post … e-heart-it
This image shows the many ways scarves can be worn: http://www.repinly.com/popular-pin/72905/1/repins/30/0/
This video will show you numerous ways to repurpose a man's dress shirt, as a note though for this to work you need to size up by 2 sizes e.g. if you wear an xs you'll need a men's medium: http://www.colourheelsdiary.com/2011/07 … r-you.html
2) Embrace the DIY aspect of fashion. Here are a few simple ones that should help:
Shoulderless blouse: http://www.minipennyblog.com/2011/07/sh … e-diy.html
Color block skirt (this one requires zero sewing): http://www.lionstigersandfashionohmy.co … skirt.html
Two color leggings: http://fashionmutant.tumblr.com/post/22 … o-make-two
3) If you're going to spend money make it count.
Girl Props does free shipping within the U.S. and has a nice mix of basic and bolder pieces. http://www.girlprops.com/
I've seen earrings for as low as around $4
Make Me Chic is a great place to pick up shoes that look up to the minute in terms of trend without spending huge amounts of money http://www.makemechic.com/
Finally thrift stores and their more hi-brow sister the consignment shop are good places to search things out if you're patient.