There is a significant price difference between the youth sizes of these shoes and the adult sizes of the same style shoes. I wear a 5 mens/7 women's size in sneakers, so in theory I could order the youth size 5 and save money. One website I read said that youth sizes are sometimes more narrow than adult sizes, but I wouldn't know if that's true for this style unless I tried them on in a store... and I'd rather order online and avoid searching in stores for them.
*ETA: Shoes have been ordered on overstock.com, in women's size for cheaper than zappos.com. Thanks to everyone for the input, especially the overstock.com link!*