My concern here is if the NPC says $47k and you ED, you are accepting that it will come in at $47k.
The argument that it’s more expensive doesn’t really hold weight, I wouldn’t think - if you need more money, I would think, by ethical standard, the student should apply RD, not ED. Or assume that if they get in, their cost will be $47k. If they appeal and get no more money, they would be bound at $47k.
We don’t know the bonus is one time.