Fully reusable rockets are designed to favor higher thrust-to-weight (T/W) ratios due to the significant impact of propellant costs on the overall cost per ton to orbit. Despite the Falcon 9 being approximately 80% reusable, the loss of its upper stage incurs greater costs than the propellant itself. Consequently, even a relatively inefficient use of propellant, characterized by a low T/W ratio, can still effectively reduce the cost per ton to orbit.