And test this idea is not so difficult. It is enough to take a small mining farm to the ISS and see what happens. And in the distant future, perhaps, they will build entire orbital cities for mining.
You're completely wrong about that, sending small packages up to space is extremely costly. (see @stompix reply)
I've read a similar thread once and the conclusion was that it would be far too difficult to send data back to earth reliably.
Can't find the other thread any more, but I think it was about setting up a mining farm on the moon or something.