I don't know what the full game costs, all in ($30?). But I'd love if I could pay some crazy amount of money, say, $150 or something, and then have an account that would let my friends play the full game, all characters, etc, when they are in the game with me.
I've convinved some of my friends to buy the game when it was on sale, but they only have the base game, and while it's great, it's kinda stale. It's been hard to convince them they should buy the expansions, since they aren't as into as I am.