I just thought it would be cool if you saved money by buying multiple features at the same time. Such as all features that lets you save some money but it would be smaller. Such as buying water and water + at the same time would be like $25 instead of $30. I feel like it might get people to buy multiple features at a time so they could save some money and also get more money to the server.
I agree besides the point of donating is to support the server, getting the feature is just a bonus andrew gives as a thank you.