Getting from Earth orbit to Solar orbit is cheap but slow with solar sailing. And the pure energy cost is not that high in getting up to Earth orbit, just 33 MJ

Getting from Earth orbit to Solar orbit is cheap but slow with solar sailing. And the pure energy cost is not that high in getting up to Earth orbit, just 33 MJ/kg (need another 32 MJ/kg to escape Earth orbit). Rockets are of course very expensive, but mass production would change that. And there is the possibility to bring material from the Moon to build stuff in orbit before a metal asteroid is captured, so everything doesn't have to be lifted from Earth.