Cost of production to mine anything in space will be astronomical so you're wasting my time even mentioning it. You might as well claim we will mine gold inside a black hole or alternate dimension. We would probably attempt to mine metals 2 miles under the ocean long before space but that is of course no threat to anyone buying at current prices.
http://www.planetaryresources.com/http://deepspaceindustries.com/Cost to start mining will be astronomical but so will be the quantities mined. Asteroid mining is not that far away in time. Privatization of space industry is bringing down costs. You don't really know whether the costs will be so high that the market won't be flooded enough to keep the price of precious metals down.
That's a futuristic concept art, you don't need that kind of structure to start mining an asteroid, and it's not a Dyson sphere. You don't have to maneuver kilometer long asteroids, small ones will do, there are ones passing close by Earth, you don't have to go to the other side of the Sun or something.
It will probably be a couple decades but you shouldn't be so dismissive of it, especially if you're betting all on precious metals
You know what youre talking about, unlike ROach who loves mixing things together with irrational explanations..which make me convinced that his longterm gold plan will be ruined if he wont listen. Thats not my problem i just gave him a good tip. I'm baffled about the Dyson spheres those belong to type 2+ civilizations while we Earthlings sticking to type 0.
Same story when i explained 3d printer to my friends years ago, they thought i was crazy. There was no such thing as ''printing'' a house out of a 3d printer, they know better now. Even NASA is using a 3d printer to print food for there mission to Mars. Within 10 years everybody will have one so people can download ore disign there own furniture. possibilities are end-less.
Idem dito with Bitcoin. Those people who called me a fool are now respecting me because they know i'm starting to get rich. (Profits are nice but thats not my main goal, financial freedom is more important to me)
I love longterm exotic technology, my calls are always on spot.
Currently i'm reading a lot about nano technology and human DNA, in particular DNA manipulation.