Paying extra for larger sizes.

I read Alicia's post on her response to "No fat sizes". It got me thinking about clothes for plus sized people. If you are ever shopping most stores charge you extra for larger sizes. I started thinking about it, and i know there is the argument that they need to charge more because they use more cloth. This raised the question for me about why they only charge more for sizes once you get in any size larger than a large. If the argument about using more cloth is used then why doesn't a medium cost more than a small and a large more than a medium. There is more cloth used in each size other than a small. So in my opinion you either need to charge more for each size up or stop charging more for "plus size" clothing.