The difference in expensive eyeshadows and drugstore ones.

This is a great article from NY magazine in which they do a survey of four similar color eye shadow quads.  You might be surprised who the winner is.  Here are the four they review:
1-Dolce and Gabanna
2-Sonia Kashuk
3-Black Opal
4-Maybelline

Read the full article here:
http://nymag.com/daily/fashion/2009/12/eyeshadow_showdown.html