I think this is one of the scariest issues facing small farmers today, especially market gardens and I fear for them.
Like Dan mentions, where I live in Maine the market gardener can sell their produce locally, but it is a very rural area and the farmers markets are saturated by customers who can afford the higher prices, the poor buy from chain stores, and generally this is a VERY rural area anyway, so in the end for most market gardeners here, the market is 4 hours away in Boston.
But with the Local Buy Local movement in full swing, and showing no signs of slowing down, it puts a hurt on this areas former market. People in Boston want local food, not 4 hours away. And with Urban Farming now rising to the front, with technology and ethically, morally and just as tasty food produced locally competing with Maine food and their traditional market; I fear for my market garden neighbors.
No one is at fault here; buy local is awesome, and I don't blame my neighbors for providing food to Bostonians...Maine used to be the breadbasket of the country after all, but Urban Farming is slowly eroding what used to be our worst/greatest problem; a rural setting. Now with old factories being converted to farms, and vertical up urban farming, a vast amount of open
land is no longer needed to grow abundant amounts of food, and a consumer who wants it produced locally can have it.