If you are going to have a gigantic ship able to carry a hundred people there will be exponential costs. And 90% of the cost would be getting it into orbit. And

If you are going to have a gigantic ship able to carry a hundred people there will be exponential costs. And 90% of the cost would be getting it into orbit. And then there will be maintenance costs. I think it would be better to just launch many small and cheap ships, then just leave them in space or let them crash into mars after dropping cargo by parachute with some air cushions. They could be carried into low orbit by a jet airplane, then use "dumb" rockets like water under high pressure in cheap lightweight tanks. And heat it up to vapor temperature using then sun.