This is not an apples to apples comparison. The Saturn 5 shed weight and was eventually two small crafts flying together on its way to the moon and down to only a smaller craft to head home. Elon’s Big Fucking Rocket (starship and super heavy) are designed to carry a shit ton of mass to get to mars. The ship has an enormous amount of cargo space and 6 fuel and lox hungry raptors to push it along. The ship uses all the propellant storage it has just to get that big bastard in orbit. The refuel part is a bit misleading as the ship will get refueled while in earth orbit by sending up starships designed to carry the liquid propellant like a big tanker truck to dock with and transfer propellant over. That will take 8-9 tanker ships to refuel completely. Elon wants to go to Mars…NASA wants to go to the moon. Mars has methane (fuel) and water ice (oxygen) needed for refueling and obviously breathing. It’s easier for starship to refuel on mars once the infrastructure is there. It takes a shitload more tanker ships to refuel the starship if it lands on the moon. Either way the first ships to go will be a one way trip. All the info for refueling is on SpaceX’s website or at least was