The economics of this could be better than you think.
A fair-sized chunk of an asteroid could contain a few trillion dollars worth of platinum group metals. If money can be found for it, a sample return mission to a near earth asteroid could probably be accomplished SpaceX-style.
A key step in all of this could be the mining of water from the asteroid Ceres, which is a much more practical destination than mars. At that point you could set up a solar or nuclear powered water cracking factory that would make large amounts of fuel available. Any needs for water in space could be so satisfied.
It's only worth a few trillion dollars if you don't actually sell it to anybody. Every kilogram they actually introduce into the market reduces the total scarcity of the resource, which means every kilogram they introduce has a lower marginal value.
It is true that increased supply -- all else equal -- decreases price, but, 1) we will find uses for the element that we don't currently use/know about and 2) we will never find infinite amounts of any resource so this means that. Prices will decrease marginally, but theres no way to know to what extent prices would fall.
Thought experiment: SpaceX is able to lasso up a 100% diamond asteroid and bring it to earth. Suddenly supply of diamonds is 1000x what it was expected to be that year. Diamonds will be worth marginally less as a result, however, it does not mean all that diamond asteroid is worthless. I am sure diamond mines would close for a bit as that asteroid is likely cheaper per unit than some other methods. Suddenly because diamonds because relatively cheaper they can begin to be used for all kinds of currently uneconomical uses. Maybe diamond fiber becomes the next typed of networking cable, or diamond asphalt makes our roads last forever, or diamond knives become all the rage for top chefs -- I don't know, but we'll find a way to use cheaper diamonds, and that asteroid is going to be worth a boatload no matter what.
Wish I had more time to think about this, but work calls.
As far as diamonds go, we already have more than enough here on Earth, and the price is being kept artificially high by a cartel. Industrial diamonds are only worth 1/1000th of what you pay for jewelry diamonds, so there's not much incentive for that.
But I see your argument.
Personally though I would want to keep the minerals up in space, figure out how to refine them there, and then use them up there. Since the cost of getting large quantities of materials up there is still rather expensive.
Yes, but by then you have disrupted the market so thoroughly that asteroid mining becomes a matter-of-fact standard and, very soon afterwards, the only feasible source of certain substances. It'll be an inversion of the status quo and if they can pull this off, this could restart our space-faring technologies.
Going beyond our planet for resources constitutes a huge step in human development - a step we're currently opting out of, but one day a mining program such as this might get the ball rolling again.
Meh. First off, you'd have an effective monopoly on a handful of industrial metals. Gold aside, the main use for these metals dissipates them: I worked at a place that consumed several precious metals for hi-tech purposes, and couldn't recover them afterwards (not economical).
I've thought people would mine asteroids in the future because they're a great source for my favorite metal, iridium. I just didn't think it'd happen so soon.
You don't need much fuel to get the materials back down. As I note below, a railgun is all you need to send the materials on their way, and aerobraking/controlled re-entry gets them back down to earth.
Unmanned cargo can withstand high G forces, high temperatures, long transit times, and there is so much material available that losses due to ablation are likely acceptable.
A fair-sized chunk of an asteroid could contain a few trillion dollars worth of platinum group metals. If money can be found for it, a sample return mission to a near earth asteroid could probably be accomplished SpaceX-style.
A key step in all of this could be the mining of water from the asteroid Ceres, which is a much more practical destination than mars. At that point you could set up a solar or nuclear powered water cracking factory that would make large amounts of fuel available. Any needs for water in space could be so satisfied.