less material, more expensive..?

I'm so confused. I bought a pair of jeans from American Eagle the other day and paid 30.00 dollars for them. Then I started thinking about how much I had paid for shorts last summer, anywhere from 40.00 to 50.00 dollars. I just don't understand, they take off way more than half of the material but yet they can still charge the same price, if not more for them. And the worst part is, we still buy shorts at that price, therefore they keep their shorts at that price because they know they can, and they know we will still buy them!