Well, players can purchase CE using real money directly from Three Rings. Once they do that they can sell it for however many crowns they want on the market, though the price is determined by the simple laws of supply and demand. When you look at the market all of the prices that you see have been posted by players. Hopefully that helps.

x means "times" and #y means the amount of units you want...

i.e. I want 1000 energy so 5321 x 10 (10 unites if 100 CE) = 53210cr