My point was pretty simple. If all you want to do is mine water or carbon, earth has these in higher concentrations and is easier to get to than Mars. In the near term, the value of water on the Moon is converting the water into rocket fuel. If the Moon had trillion of tons of water only a small percentage would ever be used as rocket fuel- sheer quantity wouldn't add much in terms of near term value. Instead of trillions of tons the minable quantity needed would be in the range of millions of tons [a square km by a meter thick of water would be around million tons- or exactly a million tonnes]. A solar panel which generated 10 kwh would need about 500 hours to produce enough energy to split one ton of water to make rocket fuel or if you had 100 mwh capacity you could produce a ton every 3 mins, or a million tons every 50,000 hrs [5.7 years]. In terms of getting to Mars, a Saturn V size booster could put about 50 tons to lunar orbit, therefore roughly speaking 10,000 tons of fuel in lunar orbit would equal 200 Saturn launches- in other words 10,000 tons in lunar orbit would more than what is needed for any NASA Manned Mars program. Now, it's improbable that much more than million tons of lunar water would be ever lifted to lunar orbit- there is other ways of getting water into the Earth/moon system [NEOs or comets] and there are other technology development which would change rocket fuel needs- mass drivers, higher efficent rockets, tethers, cyclers, etc.
Now, the Moon could have billions of tons of minable water, with millions of tons used as rocket fuel and sold at higher prices, and the remaining being used as lunar development progresses and sold at lower prices- perhaps reaching prices equavalent to what people pay for bottled water here on Earth- the water probably won't abundant enough for large scale farming, but you will have things like swimming pools and water used in various mining and manufacturing processes.