A lot of the people who sell things professionally on various online platforms know that the best deals are found at garage sales and flea markets. Most of the time, the sellers are just people who want to clean out their house and maybe get a few extra bucks out of the deal. As a result, you can often get great value particularly if you offer a price on a large quantity of stuff.
The big problem with garage sales is that you have to drive all over town to see what they have. For many people, it is easier and more convenient to just go to some place like the Raleigh flea market where hundreds of sellers can all be found in the same place. You save time and gas money, plus you can’t get a corn dog at a garage sale.