The only problem with buying clothes on the cheaper end is the quality. American Eagle and Old Navy and especially Loft hold up their ends of the bargain. You have to be careful with stores like Forever 21 - the clothes are great, but if you wash or dry or wear them too much, you can run into some problems.
Here's an example of how to dress preppy for less:
I found all of these pieces for great prices:
Necklace: Old Navy, 8.00 (Couldn't find a link to this one... Click here for a similar necklace from Baublebar)
Where do you all shop to dress preppy for less?