I understand that you probably need to set price options in the app in order for it to be accepted in the store. However, I do find the proposed "threshold" prices annoying for a donation. Threshold prices are supposed to trick people into spending more because they tend to round prices down so € 9,99 "feels" like € 9 and not € 10. They just annoy me but the evidence that they work is pretty overwhelming.
But when it comes to donations you're providing the incentive through the description, we get all warm and fuzzy that we know the servers are paid for. In contrast I found the pricing so annoying that it initially put me off paying for what is a truly great app. So how about it: €5, €12, €25, €50 and €100?
But not wanting to be too much of a stick in the mud, I've just paid up.