This is perhaps not a popular topic around here, but wouldn't it be more interesting if the houses were physically limited in the game universe?
The game can accommodate residential zones of various class (poor to super rich) and houses can be part of the economy. They are always taxed so if the player abandons the game or doesn't play for a long time, then the house goes back to the game where it is available for resell. There is also a regular upkeep fee depending on the size/class of the house.
While technically challenging, I think it would make housing a whole lot more interesting than it is now. Of course there is the issue of scaling this to accommodate to the number of users that could perhaps be interested in the grind aspect of the game.
Let the player based economy drive the housing prices up/down with time. This scenarios would be a LOT more interesting than just "this one house is magically the same for everyone".