Considering how much JL made in foreign box office, I sincerely doubt that is the ceiling. Unless it crashes and burns domestically (talking under 100M) that won't happen. Should have a healthy overseas take considering its competition is a nanny most of the world doesnt care about and a Transformers movie that seems to be lacking in spectacle. Plus looking at box office history, 4/5 DCEU films have crossed 400M+ overseas (MOS being the exception at 377). Aquaman will more than likely cross 200M+ domestic, as even JL and MOS managed that. The holidays should also help it out in that regard. I'd say the floor is 600M, going by past history. PS: You can't compare MCU and DCEU films at the box office and use said comparison to predict how a new MCU/DCEU release will do because the two have completely different box office patterns.