Auntiegrav made a good point : parisian markets are expensive, and mostly (though not only) target well off parisian middle class.
Though there are cheaper alternatives : I'll mention three here
Buy local quality food, sourced directly from local farmers coming for a weekly sale at your neighbour's house.
How to use : Sign in on the website, choose the "Ruche" ("beehive") closest to where you live. Order products once a week through the website. Pay online. Get it at the weekly distribution and meet farmers, volunteers, neighbours. Go home, cook, share, smile, be happy.
2) AMAP : Association for Maintaining a Peasant-based Agriculture.
If you live for a year or more in a city, you can get together with nearby consumers, and get in touch with a nearby farmer. Get the money together to pay him ahead, in the spring, and get weekly baskets with his products. More if good output, less if bad output. Fair !
Paris price is 12-17€ for a weekly basket, usually enough for 1-2 peeps. Bigger baskets available. Don't mind the weird name, they are wery widespread in France. For Ile de France, find the nearest one to your house here : http://www.amap-idf.org/trouver-une-amap_33.php
For other provinces, google is your friend, they are everywhere.
3) Buy directly from farmer. Some farmers are brave enough to try and e-market their products directly to the city. Here is one very good and affordable one near Paris in Cergy : http://panierbiocergy.com/
4) Move your ass and go to the farm ! Most of them have websites, phone numbers and google maps address now you know !