That's a money laundering deal. Here's how it works: Somebody, let's call him a bad guy, has come into some money that he wants to clean up for tax purposes (as Master P has told us in "Ghetto D", clean money lasts longer than drug money). He lists a piece of junk (or "art", or real estate, or a car) on ebay or CL at a ridiculous price, and gives the cash to someone who is less concerned about the tax man. The second party then uses most of the cash to buy the object from the bad guy at a stoopid price, keeping a % of the cash for his troubles. The bad guy now has a legitimate pile of cash he is free to invest, and if the tax man inquires and to the source of his recent cash infusion, he points to the ad. This is the main reason for the existence of e coins, and why they remain unregulated.
Wired magazine had an article a few years back on how criminal gangs in Puerto Rico were using the country's lottery to launder money. The bad guy tells his army of drug dealers on the street to make sure they tell all their customers that he will pay cash for winning lottery tickets- the ticket value plus 10%, for example. Someone gets a $1M winning ticket, the bad guy gives them $1.1M cash and takes his winning ticket to the lottery office and collects his $1M in now legitimate cash. IRIC, one gangster won the lottery multiple times in the space of a couple years doing this.