Comment by asadotzler

My guess is we'll find F9 boosters good for between 20 and 25 launches before refurb becomes expensive enough that it's better to weld up some new tanks and build another batch of Merlins. There will be a pretty big range I think. We already see they've got favorites that are far outpacing the rest of the fleet presumably because they're easier to refurb and refly. So, I think some will retire around 15 flights, and some around 30, with the low 20s being the top of the bell curve.