Bittertruth,

The technology for mining celestial body is not ripe yet. mainly because of the energy problem. We have not develop the efficient solar panels to collect energy for heavy duty work.There are other  problems too  but most of the problems we can solve within 20 years. Main problem is energy.

A mini mining set up in celestial body will probably require 250 MW of energy supply. Solar energy harvesting system is not yet developed to generate that much energy. The best option available today is nuclear power plant. 
We are not technologically sound to set up a 250 MW plant in any celestail body because of the cost 


So, instead of mining the celestial body it is better to look for alternatives available on earth which might be cost effective

But we should dream about all possisibilities. This is what keeps human kind move forward. One day it will be possible to mine the celestial body, just by

1. Reducing the size of 250 MW nuclear power plant by 1/10. One day human  will develop technology that will reduce the size of nuclear power plant by 1/10. If this happens it will be economically possible to set up a nuclear power plant in asteroid or in moon.
2. Develop solar technology that will be able to collect and store large quantity  of solar energy.
3. Development of another power generating technology. This could be anaerobic bacterias which will feed on the materials available on those celestial bodies and generate power.

Dont forget 

The computer used in Moon landing onboard Apollo 11 had  

1. 64Kbyte of memory and operated at 0.043MHz.
2. Computer weighed 30 KG
3. Display and keyboard unit weighed 10 Kg
Display unit (upper one) and main core of Apollo guidince computer (below)

This was in 1960s, In 2012, we laugh at it