The Paris marchés alimentaires are great, but certainly no more so than a typical American farmer's market. They are, as anywhere, dominated by distributors who sell the same stuff you'd find in the neighborhood produce-shop (these are what's shockingly absent from American streets). A few of these have connections to producers or suppliers of unique products. For example, most have peruvian mangoes and bizarrely, avocados are 3 or 4 for 2€ , definitely a good deal. One vendor had these, plus the only unwaxed Italian lemons in the entire market! (Everyone else's were neither.) Some sell olives out of giant tubs, others out of smaller vessels with their own flavoring additives.
Then there are the few producers. The scale of Belleville/Père Lachaise (they abut one another) is approximately the same as Soulard in St Louis, but all stretched out in the middle of the boulevard. There is one place with yellow turnips; only one with interesting colors of carrots; one or two with unwashed mâche; one grower of multitudinous varieties of apples (I got a selection the other day, one was really not good, one was excellent so far)… but the ratio of actual producers to distributors appears to be approximately identical to Soulard.
There are a few bakeries, creameries, butchers – I haven’t begun to investigate many of these, but none looks great. I bought a camembert au calvados from one of the smaller, more focused fromagers; he also had free-range eggs (in contrast to the palettes of mass-produced ones elsewhere). From my more or less regular bakery (still on the fence about them, really) I got a small bread for the train to Amsterdam tomorrow – so apple, camembert, and boule de campagne.
There are several biologique markets, which I expect will be more like Green City. The St-Quentin covered market has some nice looking butchers. My charcuterie allegience is already in the direction of the place by Voltaire, at least for pork products.