I thought I read it as well, but I'm no longer sure. 1) it matched the ~BCX of riftwatchers airdrops, which had about the same sales numbers so that made sense and 2) it was the number they used in the test run in the QA server. But someone told me that the number in the QA server was arbitrary and not necessarily the actual number.

If it does change from 4000, the ROI will obviously change. I'll probably re-write this when actual conflicts are announced to give better specifics with fewer assumptions.