Let's see.
Since Arthur is bombing, and Snatched cannot be considered competition, 60 million is locked for this weekend but it can go as high as 72 million.
That will put it in 250m domestic in 10 days.
So next week, the anticipated number is around 40 million which will bring it around 310 with the weekdays added.
4th week total will be 30 million, double features with POTC will help, so we're looking at at least 350.
Another 20 million until the end of its run will take it to 370 domestic.
Now the international is a bit more tricky, but in general there is a 25% rise at least in most markets, so the floor for that would be 550, but it can do as much as 600, maybe more.
1 billion is possible, but only with great legs. We will know by next week.