This is certainly an interesting idea, especially for people like me who dont have the money to buy stuff. But I would not actually like this being added.
First, you're using the server but not supporting it financially. So why should it reward you?
Second, I feel cubits are already a treat in themselves that allow you to get things with real world value using in game currency.
Third, cubits arent that hard to get. By voting, Gary, and buying from people you can pretty easily get dozens a day.
Fourth, if someone else buys you something when that person is determined to have a $0 purchase history, it gets ruined.