Yes but let's put that in perspective. To get one rocket into LEO currently costs about $100m. That's equivalent of digging up about 1M tons of iron. Obviously

Yes but let's put that in perspective. To get one rocket into LEO currently costs about $100m. That's equivalent of digging up about 1M tons of iron. Obviously it's a lot less for more valuable materials. It looks like platinum is about $1k/oz and Google tells me there are 32,000 oz to the ton so that's about $32M or 3 tons of platinum. Now obviously if you were living in space you wouldn't need to get things onto or out of the Earth's gravity, which is where things get really expensive, but the launch cost puts things in perspective about just how expensive it it to do anything in relation to space. So take that platinum. Where is it coming from? The asteroid belt? How expensive would it be just in fuel to go and get it and possibly refine it (assuming you don't find a solid lump of it)? What energy source are you using? People tend to think too simplistically about energy. Like the holy grail is viewed as getting more energy out of fusion than you put in but fuel is only one cost component of energy. Let's consider: - How expensive is a fusion reactor? - How big is it? - What is the energy output? - How much does it cost to maintain? Add all those things up and there is an amortized cost to even fusion energy. So start adding all this up and the delta-V required to get all of this to and from wherever it comes from and it's hard to come up with an economic model for how this can possibly work.