Too bad this article is completely pointless and avoids the real issue.
Its patently obvious that if the costs go up in producing something then the producer has to sell it at a higher cost to be viable as a business. It costs more to grow 'ethical' lettuce than commercially grown lettuce. This gives commercial growers a huge advantage in terms of pricing. But the 'ethical' grower makes a better product.
Not everyone can afford Mercedes Benz.
The real difference - something lost on the writer - is that not only does the farmers market buyer get better quality, they are also contributing to local economy, and - here's the biggie - they are supporting agricultural methods that are sustainable, not destructive. Commercial agriculture is environmentally disastrous for a long list of reasons.