Production cost - 280 million - 300 million
this is a much bigger movie than winter soldier which cost just shy of 200million . with all the action and varied special effects sequences and the huge ensemble this is a way bigger movie no doubt it will show
Marketing- 100 million
Backends - 100 million+
- Marvels backends are legendary and has helped RDJ earn between 70-90 million dollars a year for the last 4 years and its made him the Highest paid actor for that period too. In this case we know all the rest of the team have better contracts not to his level but definitely not bad either
If you add up production marketing and backends, its roughly 500 million as we all know you need to do double that at the box office just to break even.
So 1 billion is the minimum it needs.