In terms of the fuel needed to get there, the closest bodies to Earth are a set of asteroids whose orbits are very similar to that of Earth. Some of those have hydrated minerals, meaning chemical processes can extract water from them. Some may even have water ice buried in their interiors. Water can be turned into rocket fuel, and rocket fuel stored in space can be used to refuel rockets, which means where they can go, how fast they can get there, and how much they can carry, all increases dramatically. Some in the space industry predict that with the right robots, such fuel mining could reach profitability before any such industry on the moon could.
This may be the case, in particular if it turns out that mining water ice at the lunar poles is harder than is hoped, or the reserves there are less than anticipated. Either way, once asteroid mining matures, it will be concentrated in lunar orbit, and most of its human staff will be located on the moon until such time as space stations of massive size makes it possible to locate even closer to their work in comfort and safety.