How do people feel knowing they have been ripped off?

What do you mean? How do they feel having sold something to a person running a business reselling things? If they want to get the fullest amount possible, they should go to eBay and hope for the best.

Here's a couple links that might help you understand what he does a bit better:
http://en.wikipedia.org/wiki/Reseller
http://en.wikipedia.org/wiki/Overhead_(business)

Well said. Sellers- inform yourselves and have the common sense to know that you are not selling to the ultimate buyer !