I agree with the idea of giving an epeen for a larger contribution. Extra BP’s and/or a special epeen for donating more than the minimum required for Ep2 would be great incentive. From a sales and a buyer point of view, it is win-win to spend more since you gain more, yet it would not alienate those who can’t afford it if you still allow the option to pay for Ep2 with the minimum cost (but without the frills.)

The fact that this game has so many loyal players who are willing to pay more than $10 is pretty impressive, it would be a good sales tactic to reward their generosity with a little extra BP and special epeen.