That's blasphemy! Flea markets are a cult religion...it's not what you buy, it is the experience...and PayPal sucks!
To find something on ebay, you have to know what you are already searching for, or looking over a vendor’s list for a second thing to buy, or looking at a category.
At a flea market, it is all of “equal” weight. Something jumps out at you, it is a hunt.
Again, the people who sell on ebay will sell in both places, first buyer takes it.