I have seen Ebay items (such as books) that have a Buy It Now price of as little as $3.74 with free shipping. Books can be sent as media mail but the lowest rate is still $2.63. I calculate a profit, after fees, of about $0.60. These do seem to be high volume dealers. Do they actually work on such a small profit margin or am I missing something/
If they sell a thousand books a week that way, that’s 600$ a week. That’s more than you make flipping burgers every night.
They need such low value items to become known and grow. Don’t forget they also have higher value items with more margin.
they might also have mass shipping prices, which are lower than what you see.