I was reading through his latest newsletter and noticed a link to Paris flea markets. He really had a wealth of information in there like photos of items he's picked up and tips on getting there. He also discussed brocantes, bide-greniers, and braderies, which are their version of our garage and yard sales, along with Emmaüs stores, which are thrift stores that sell donated items to raise money for people in need.
It was really a fascinating article and the photos in it alone are worth seeing. There were lots of tips on how to pay and so on. It's definitely a good article to bookmark if you have any interest in flea markets or other second-hand sales while you are in Paris or the surrounding area.
https://www.davidlebovitz.com/paris-flea-markets-and-thrift-stores/