There are a few reasons why many people are willing to pay more for reselling than what you would expect. I think the most likely reason is that people buy the resold hosting expecting some services that are not included. The other reason could be that people do not do their research. Many new webmasters see a post saying "UNBEATABLE PRICES" and the think, wow.. that must be a great deal. So they end up paying more than they should. Like they said, it all comes down to marketing.