Reportedly the budget for Marvel's future space epic "Infinity War' will have a budget of 1 billion dollars. Of course, right of the bat this sounds highly preposterous, but considering the intake of cash that Marvel and Disney have gained from the Marvel Cinematic Universe alone, it is quite impressive and well over several billions of dollars.
Now wether that success would warrant a billion dollar budget can be debated, but if this is true (which it may or may not be), then we can assume that Marvel expects "Infinity War" to be a very profitable set of films.
Also, half of the actor budget that Marvel has set for both films is going to one Mr. Robert Downey Junior. No matter how you feel about the actor we can all agree that he has a large box office draw, almost as massive as Dwayne 'The Rock' Johnson.
http://www.latino-review.com/news/avengers-infinity-war-to-have-a-budget-ofone-billlllion-dollars