Vegetables are damn expensive.  This year is particularly bad as hurricanes devastated Florida.  I think that the supermarket model is rather wasteful as far as produce is concerned.  Fruits and vegetables are grown on industrial scale is few places of the continent, transported from one coast to another, and then displayed and sold by staff that has no idea what are they doing --- no wonder, supermarket workers cannot afford vegetables, and do not even ask about fresh herbs.

Supermarkets are good with industrial foods and packed meat.  Of course, convenience stores are typically much, much worse -- although ethnic stores are sometimes good.

Markets are much better at handling produce.  Sellers are knowlegeble about their wares, they waste less, they can explain anything to a buyer and offer advise.  Produce at markets can be twice cheaper than in supermarkets.  Local producers who offer more fresh and tasty produce, if not as well looking as industrial varieties have easy access.

When I was a grad student in Boston area, every week I schlepped with my wife, with big knapsack, to Haymarket, to stock fruits, soe vegetables, imported cheese and frozen fish.  If you know what you want to eat, you can walk several miles once a week (we were returning by subway).

I think that "farmers' markets" and education are the best solution.  And suburbanites could use them too.