I just think it's the name, rather than a band or solo.
Biggest bands in the world, will get the same as the biggest artists in pop and hip hop.
Although due to bands being pretty much waning in popularity, perhaps not commanding the big fees.
Is logistics even a criteria?
Yes, that is genius.
Cheese toasties (and plain old cheese sandwiches, to be fair) go perfectly with tinned tomato soup. Cheap and cheerful of a winter's evening.
I have no idea, quick google resulted either something between 2.5-6million for FF and Eminem, or 500k+ for FF. Eminem and Madonna is probably pricier than FF, but the gap is much smaller I think than between Sheeran and the National. Anyways, as you said you can pick any two artist to make it like you are right, but I think one average a band costs more and also takes much more logistic to move everyone and everything that comes with a band.