The prices for player housing are going to be based of PC gil income, not the average income for an average citizen of Eorzea. It would be a mistake to base estimates of cost of living on something intended to be a gold sink for the game.
"Song dogs barking at the break of dawn, lightning pushes the edges of a thunderstorm; and these streets, quiet as a sleeping army, send their battered dreams to heaven."
Hipparion Tribe (Sagolii)Â - Â Antimony Jhanhi's Wiki