I thought of this while flying to Planet Manhattan
Space Station: Outpost (2000 credits), Cargo yard (6000 credits), Shipyard (10000 credits), Freeport (25000 credits). After purchasing a space station you would hire mehanics, bartenders, and try to bring in some merchants. The cargo and ship yard could make you money.
Planet Base: Underground base (2500 credits), manufacturing plant (5000 credits), Science base (6500 credits), settlement (30000 credits). But to first settle on a planet you would have to scan if it would be okay to settle a base. What do you think?