Here is an article on the viability of indoor urban farms. As a graduate student in the 1990's I visited a hydroponics farm in Texas where they grew strawberries and combined it with fish culture. I also visited an indoor shrimp farm that used recirculated salt water I do not know today if they are still in business. At any rate, the idea of growing food in crowded cities is interesting. In order to compete with traditional food sources they use different marketing strategies. Currently, food produced in this way is more expensive than that of regular grocery stores, but less expensive than that of organic food markets like "Whole Foods".