To dream of a flea market represents your wish to get the best opportunity possible. You may be down on your luck and are looking for a break or a chance to "get your foot in the door." Feeling good not having to take advantage of a good opportunity right away.
Positively, a flea market represents savviness or your motivation to get a better opportunity or deal than you usually get. A mindset that enjoys not being desperate while you consider all your options.
Negatively, a flea market may reflect too much of a casual attitude about taking advantage of a good opportunity. Risking losing a good opportunity because you are wasting time waiting for something better to come along. Risking losing an opportunity because you are wasting too much some waiting for conditions of your liking to improve. A non-desperate attitude that is not appreciating how lucky it is. Waiting for the "perfect bargain deal" when it might never come. Missing out on good opportunities because you were not taking them seriously enough. A naive belief that other people are losers who will not give your good opportunity away to someone else.
Example: A woman dreamed of being in a flea market in a churchyard and then walking into the church to see someone desperately dragging a bag of rice outside the church. In waking life she had been offered a job opportunity, but then complications kept arising that delayed her ability to take the job making her believe she was never going to get the job unless she tried harder. The flea market in this case may have reflected her naive belief about the job opportunity being easy and always open to her while she got distracted with other things in her life. She may have taken too much liberty in believing she could enjoy herself considering whether the job was what she really wanted.