[IXxXI]

Space junk in orbit is much more accessible than the nearest asteroid.

Its also far easier to recycle and salvage than refining raw ore.

[toss1]

Both true - that's what makes it seem feasible.

I suppose the real comparison is [cost of refining material in orbit] - [cost of collecting on orbit (which must be done anyway)] vs [cost of refining it on the surface + launching it into orbit].