Dear Bean: here is URL with definition of "flea market".
http://ask.yahoo.com/ask/20010709.html
It is a disparaging term referring to
low quality and dubious origin of the merchandise. My wife and I used to enjoy going to them
because we often did find real bargains. I still have in my desk a ream of top quality legal
typewriter paper I got for two bucks. I occasionally use it for letters on which I want to add
diagrams, or a handwritten P.S. I got three dozen excellent jack-knives for a buck apiece,
which made very acceptable presents for ten years. The flea market covered perhaps six acres.
You could spend all day there and not see it all. Most of it was junk, but interesting to browse
through. Admission was a buck per head.