I understand the need for an increase in revenue, however most people overreact to even a slight increase in cost (asking on a forum isn't exactly unbiased), possibly resulting in a decrease in revenue. I suggest you simply advertise supporter more, such as putting a "support osu!" Button on the opening page above the link to the site. This button would link to the buying supporter page on the website or if you wanted perfect integration the button could link within the client itself.
Demand curve:
with an increase in demand as you can see, the increase in demand would increase, but the price would not increase because you have infinite supply of supporter to give. therefore increase in revenue (area under dotted line = revenue). You could also increase demand through other means such as increases supporter perks.
what is being proposed, an increase in price alone is more likely to give these results.
As you can see the increase in price of supporter results in a decrease in demand and the profits are likely to remain about the same. (again, area under dotted line = revenue)
Tl;dr I believe if you simply increase demand through advertising, profits would be greater than simply increasing the price of supporter a slight amount.
Demand curve:
with an increase in demand as you can see, the increase in demand would increase, but the price would not increase because you have infinite supply of supporter to give. therefore increase in revenue (area under dotted line = revenue). You could also increase demand through other means such as increases supporter perks.
what is being proposed, an increase in price alone is more likely to give these results.
As you can see the increase in price of supporter results in a decrease in demand and the profits are likely to remain about the same. (again, area under dotted line = revenue)
Tl;dr I believe if you simply increase demand through advertising, profits would be greater than simply increasing the price of supporter a slight amount.