They have to land a nearly empty booster. They don't need as much fuel as they needed to launch. Anyway, here are the economics according to Musk https://www.i

They have to land a nearly empty booster. They don't need as much fuel as they needed to launch. Anyway, here are the economics according to Musk https://www.inverse.com/innovation/spacex-elon-musk-falcon-9-economics https://www.inverse.com/innovation/spacex-elon-musk-falcon-9... The breakeven is closer to 2 launches than to 3, so 3.