I don’t think it’s quite right that Disney will make half their money back on LucasFilm in just one Star Wars film — but it’s likely that they’ll make it back in a trilogy.
Disney paid $4bn for LucasFilm. The budget for The Force Awakens is an estimated $423m including marketing and distribution. x3 = $5.27bn for the property and the three films.
50% of the purchase was from cash reserves, while the other 50% was in stock. So suddenly, the total cash outlay is $3.27bn. Let’s assume the whole amount paid was debt, so add a 3% annual interest rate and assume a five-year period, bringing us to $3.8bn.
If the films really do take in $2bn each, then the cash cost is covered in two movies (and, indeed, half the cash cost is covered in one). More likely, it will take three. If each one takes $1.5bn, Disney makes a tidy $700m profit.
Then there’s the remaining $2bn in stock. If we take that into account, then, assuming there isn’t an obvious demand for two trilogies, Disney would need to think about spin-off movies. Which, of course, they are.
All assuming that these new movies are better than the last three, which they pretty had better be, because Jesus.