Entropia Universe

300 trillion ISK is the figure that was landed on amongst my correspondents with experienced marketeers in the game.

Now, again, I have to point out that ISK cannot be sold for real world money within the rules of the game, so please take this dollar figure as indicative only, but that would still comfortably make this item worth 2.4 million US dollars, by far the most expensive virtual item in existence, beating out the Crystal Palace space station and Club Never Die from Entropia Universe quite handily.

This structure was made as a joke by the game developers, who more or less said it is likely never to be built in what can only really be seen as a blatant challenge to EVE Online's player base.

But it must be remembered that Titans, the giant spaceships that now form our martyrs, were believed by the game developers to only be limited to a few dozen units when they were first introduced.