I recently purchased this dress for a little over $6 from Target.
Needless to say, I 1. am in absolute love with Target's clearance section and 2. will have no trouble fulfilling the "free shipping over $50" criteria.
P.S. Please ignore the yellowish tint...I had to play with colour a bit so the picture would accurately represent the grey in the dress.
P.P.S. This dress is acceptable for office wear, right? I'm going to be interning in a business setting very soon and I am currently on the hunt for things I can wear that won't induce massive overheating.