I want to start selling again. I stopped because of a bad experience but think Ill try again. Can I ask (for the people that sell) do you buy things off Amazon or online shops to resell on Ebay? I used to do this and it was profitable.
I do when they have a sale on. But for items that I've researched carefully and that I'm confident will retain a good resale value as what you need to be aware of is that if you can buy it online and sell it for a profit then so can the competition so you may find the market quickly gets flooded. Therefore I tend to focus on merchandise from long-running film franchises and TV series like Marvel, WWE, Star Wars, etc as that's the sort of stuff that will increase in vale when there's a new series on or film out. Or I'll buy stuff cheap now and keep it for Christmas to sell on for inflated prices then as things like Furbies, board games and bop-its do well at Christmas. So basically you've got to think about the long-term when buying stuff online to sell for a profit and be prepared to be sat on stuff for months without it selling.
One exception to this is buying stuff at eBay auctions. I'm often buying stuff cheap from an eBay auction and then putting it straight back on eBay when it arrives as a buy it now for a lot more money. But again this requires careful research into figuring out what sells and how much profit you can make on each item before you place any bids.
If you're looking for the highest profit items then as
@homie says the best places to look are car boot sales and auctions