my guess is that it's the "most expensive" because you register, you pay, and then it gets seized and resold without your knowledge and without a way to appeal it. The author said games.ng got sold for 10,000USD/year (which WOULD make it the most expensive).

I think the seizure adds to the price. Imagine ycombinator.com or even reddit.com sold to the highest bidder? Millions in damages.