After a long cold winter, flea market dealers are often willing to barter or lower prices via sales. Towards a month's end--or even at the first of the month--is quite often the prime time to get on the bargains.
This helps the dealers from paying their rent (and possibly give them some cash to buy more stuff after they pay their rent).
If you see something that you like--try making an offer on it. Keep in mind not to make it to low--you just might walk out with it if the price is right.