How to start your own eBay business
I used to buy on eBay and sell on Amazon. I sold software. You can pick a category, study it, and then look on both eBay and Amazon for resale opportunities.
Chances are you'll have some growing pains and you'll make some mistakes but if you keep going you can make money. One thing you have to watch with Amazon is that they may not let you sell everything that you want to sell. Before you buy it on eBay you need to try to list it on Amazon and see if they'll let you.
I used to sell software because it was relatively expensive and cheap to ship. You don't want to try to sell 99 cent hardcover books.
With software, both eBay and Amazon got more and more difficult when it came to selling used software. In my best year I made $22,000 for working about 3 hours a day from home. I bought software on eBay and sold it on Amazon from the fall of 2008 until March of 2016.