I can't remember what the link was, but there was a company selling the moon by the acre for like 100$ per acre. I will Google it. I wonder if those people who bought the 'property' complete with ownership certificates will have to pay landowner taxes...

EDIT : Not sure if this is the site I saw several years ago or not, but this place 'The Lunar Embassy' claims it is the only authorized 'retailer' of property on the Moon, Mars, Venus AND Mercury.
http://www.lunarembassy.com/They sell it by the acre at around 19.95$-22.95$, and you get a 'Lunar Deed' as well as a 'certified' copy of the 'Lunar Bill of Rights'. Nice...
I can guarantee one of two things. Either the people who bought this will be required to 'forfeit' their portions of the Moon they 'own', or the government will charge them the same taxes they do any landowner.

EDIT#2 : They also charge 1.51$ 'Lunar tax' as well as 12.50$ shipping and handling. So you pay about 45$ per acre, and they claim they are the only authorized retailer of Lunar/Extraterrestrial property. So if there is an alien base on the Moon, they may be trespassing on your property. Just sayin.