I have now added a donation stats section to the server status on the right side bar of the frontpage. You can see for example today:
Server cost so far: 2835.00 USD
Donated amount: 1572.09 USD
Balance: 1262.91 USD
So the overall costs since the server is live is 2.8k USD and all the donations that came in since then made up for more than half of that! Thanks again to the donators!