This is the better of Mississauga's two flea markets since it's not as crowded and the items are neater though it's only open on the weekends. The entrance btw is beside the Aldo outlet down the stairs going to the basement if you're inside Dixie Outlet Mall. The place is a bit of a maze so I'd recommend staying close or having phones on if you're with a family.
Anyways it is a mix of junk sprinkled with useful stuff especially now that cell phone case and cheap electronic shops are everywhere. Not all the knock-offs are bad though, I don't mind a knockoff soccer jersey if it's at a cheap discount. My favourite stores include the record stores, the antique and small furniture stores, and the store that sells hockey cards (the hockey card place sells full sets and signed singles, not a tonne of places to get that type of memoribilia now sadly since those stores closed down). This is also a fantastic place to get cheap kids toys from because there's a place that sells a tonne of hot wheel cars and lots of action figures from other places.
I'd recommend going here and taking the time to browse through stuff alone rather than being in a rush. Don't plan on what to get, just pick out something neat if it catches your eye and is at a good price.
A good chunk of the vendors don't mind giving a bit of a discount but barter within reason (ie, don't expect to get 50% off something already cheap). Good way to go is to ask for a discount if you're buying multiple items like $5 or so off a $30 purchase if you buy multiple CDs or books. Also just because it is a flea market doesn't mean that everything is gonna be cheap or discounted. I'd avoid getting something expensive which needs to work and preferably have a rebate such as expensive electronics or expensive jewelery from here. It's not for everyone but a couple trips when you have time wouldn't hurt and you might find some sort of gem. People who fix up old furniture and antiques for example seem to be getting stuff from here all the time.