to make a profit? Say I bought some memory sticks of ebay for £20.00 are there any marketplaces or websites which I could sell these for more than I bought them.
If you mean USB pen drives, I don't regard £20 as much of a bargain. Any site allowing you to sell items would most likely charge for the service simply to stay in business (eBay sellers have to pay commission to eBay on every item they sell)