[nine_k]

Mining an asteroid far away and then spend fuel to shuttle material from it to GEO or Moon seems rather uneconomical.

I would suggest finding a small enough (a few dozen kilotons) space rock made of a valuable / precious metal, and brought to it a large solar array and an ion gun. Metals make good ion gun fuel. Slowing the asteroid down to fall to an elliptic orbit around Earth, and then righting the orbit to put it on GEO or drop it to.the Moon seems doable with a rather limited use of mass. Technology permitting, a large enough solar sail could help slow down / steer the rock on its way towards Earth (or Moon, or Mars).

[withinboredom]

The problem is, a single accident or mistake can put the entire earth’s population at risk. It seems highly unlikely we’d bring big rocks back to earth.

[Kim_Bruning]

The fuel cost to shuttle the materials back would be fairly negligible. The main cost to getting anything into space at the moment is the initial launch to LEO. (This equation changes if you're not actually launching your mining vessel from the earth's surface)