If you really want an incentive to grind why don't you have someone stake you?

That way you have an obligation to your client to put in at least 60000+ hands a month. If they stake you enough for you to play at the next highest level and by your OP I would say it would be 25NL, you would profit more, have a very low risk factor, and be forced to play more hands and want to knowing that once you finished the run you'll have made enough money to keep playing at 25NL.