Originally Posted by
drvannostren
In a couple of instances I've asked even using the words "can I buy something from the buy on board menu?" and had them serve it to me free, but that was in lieu of a J class meal. I forget which flight I was on but the 2 options were totally unappealing to me but I did wanna eat. Different situation, but as others have said, it never hurts to ask, you just have to be prepared not to argue if you get told no.
This. Interestingly, when using your exact words I have also been told "let us serve economy first and see what is available" as they can run out of items and the FA in question wants to be fair to those passengers.