Lets start with the latter. A business plan for any venture will want to establish your Niche, Right? Your market research should reveal who is growing what, and selling to who, and at what price. Based on this formula, I would not consider doing research on another urban lettuce farm, unless I could compete in price and quality. I am not an expert. However, my first thoughts for indoor growing would be cost of utility as a major overhead. Again, I am not an expert, but I also would be hard to convince that lights could do better than the sun. Not to mention the cost of facilitating an indoor grow. Will your projections serve that amount of debt? How about the cost of leasing, renting or the long term liability of buying? Industry has left for foreign soil, abandoning industrial sites, so finding a facility might not be too bad, unless the facility was much newer and had all the modern amenities. Niche in a crowded field requires looking at every station, from overhead cost, what to grow and who to sell to, to get the biggest return.
For example, If I had an Italian restaurant with a fussy chef, I would want to find a supplier who could deliver the tastiest fresher Italian Pasta or Stuffing Pepper for my customers. The cost might not be their main concern. And if I wanted to save on utilities, I might want to use the sun and a facility that cost less. Being able to Garden in Northern Zones might not be as difficult nor have as short of a growing season. By facing the Vertical Eco Garden south, it functions like a solar panel. Sun that is lower on the horizon compensates by hitting the vertical garden more directly. The Northern and Midwest gardening season can start earlier and grow later into the autumn. If frost is in the forecast, the Vertical Eco Garden mounted on mobile stands can be moved indoors, where the stored solar heat could keep them from freezing saving utility cost thru the night. I imagine they could be linked like kiddie train cars at the zoo. One more advantage, the potting soil amending and exchange can be automated.