I also have a friend that does this. He made 28k last year buying stuff from Goodwill and flipping it on Ebay. Of course I go
through his findings and nab some stuff before he
throws it up for sale lol. I've grabbed some old NES games, Cubs gear, and some other random stuff from him. It's actually crazy some of the prices Goodwill sells this stuff at. They clearly have no knowledge of most of the items they
buy and sell.
They don't buy; everything they receive is donated, so it's all gravy to them. Also, they know the values. They just have way too much stuff coming in to take the time to market it on Ebay. In fact, the stuff that actually makes it into the stores is just a small fraction of what they process. At the Salvation Army, the major action happens at the auctions they hold every day at their processing centers. Used to buy books by the bin every day at those auctions. They try to sort it and pick out the best stuff, but they really don't have the manpower, let alone skilled workers, to properly sort through it all, which is good because it means that great books got routinely dumped in with the regular stuff. Some days, pure gold, other days, 500 lbs of scribbled-in coloring books.
And even the amount they sell at auctions is nothing compared to what they recycle/throw away. At the auction I attended, they had 4 huge haulaway bins, one for appliances, one for scrap metal, one for mattresses, and one for unrecyclable garbage. Every day they filled those bins to overflowing and hauled them off to god knows where. They also processed clothing at that facility. Forget about what you see in the store...you would not believe the amounts of clothes the SA processes. They had a huge compressing machine there, they'd dump clothes into it with a forklift, then squeeze them all together into a huge, car-sized cube. They had dozens of those cubes stacked in the warehouse, waiting to be sent to China, India, etc. from what I was told.