If you played 8 hours a week you will be spending 40 cents per hour to play. If you enjoy the game you'll be playing far more than that most likely and the price/hr would be quite low. If it seems high you should compare it to other games. If you payed 40 bucks for FFX and played it for 100 hours that comes out to 40 cents/hr. I'd say a lot of people play one player FFs in that ballpark and none of them complain about the price.

The price really isn't an issue unless you just don't like the game. In that case stop playing and stop paying and you'll have spent around as much as you would've for a one player game you tried and didn't like.