Other than the obvious (plane tickets, accommodations if so inclined) what types of things are best, or necessary, to arrange in advance of a Budapest visit? For example, are there better online prices for local transportation vs. buying in Budapest? Or museum/sight cards? I can imagine there are things like specific performances, popular restaurants, that might need to be booked well in advance, but I'm thinking of the bigger "tourist passes" that might be of interest, or of special events that might be coming up in late August.
Thanks for any advice.