We seem to get a lot of questions about how much money one needs for a holiday in a given place, these are invariably closed (correctly, imo) as opinion based.
What about a question like "What resources are there for working out how much money I need for a holiday?" where the question specifically didn't mention places or duration. I think that's on-topic but may be too broad ...
I was thinking someone (i.e. me) could ask/answer it (maybe as a community-wiki) and then direct any of the country specific questions to that answer.