I think the way forward is making Graal free to play with the addition of using grelats to obtain special equipment. It doesn't even need to have stats. I've played plenty of other games where they offer the chance to use real money to buy a cool costume for a month or so. I'm sure people wouldn't mind paying a few grelats to look awesome for a while.
And like you said, offering a means of improving your exp intake for a period of time and various other items like that.