I was thinking long and hard about this and thought it was very neat, it came to me while playing Animal Crossing Wild World a while back. This is how it goes if you haven't played AC.

I would like a script where you donate money and after a while you might get something out of it in return.

For example, let's say Luna, the main character of your story, goes into town hall or something. There is an NPC there behind a counter that'll ask you when you talk to them "Would you like to donate to (insert a town, school, etcetera)?".

Then you'll be able to choose from Yes or No. That'll be done with eventing. But if you choose yes, you're able to insert the amount of money you'd like to donate, be it all of your money or a single dollar. After you donate little by little every so often and you finally reach 2000 Money in total donations, a switch'll be turned on or you'll recieve a special item (or both if possible). This can happen several times, you go from 2000 total to 6000 total and you get another reward, always building off of a total donation number. The amount you've donated doesn't reset or anything after you've gotten your first reward.

I'd really appreciate it if someone could help me out with this, it'll add a more interesting point to any game. Unless you're stingy.

EDIT: Numbers used here are examples. ._.;