Maybe it's a good idea to somehow, somewhere prominently show last month's relay costs, broken down in those 3 area's so people have an idea of what it costs to host these relays and additionally show a "drive" of how much of these costs have been donated.
It's probably hard because you would have to do it client sided and all/most clients would have to implement this.
It's definitely not an end-all solution but giving insight in costs and covered costs at least gives people a general ballpark idea of what we would need to cover in the current situation and make it more likely to pay their part.
Definitely an idea to have that costs public