The real cost of the "extra fuel" was really in making the base rocket big enough to address the majority of the rocket without add-on boosters. Then you alway

The real cost of the "extra fuel" was really in making the base rocket big enough to address the majority of the rocket without add-on boosters. Then you always have leftover fuel for more moderately sized satellites. And in terms of design simplicity that might have been worth while before considering reuse.