You could bag yourself a bargain at the car boot sales.
If you know a thing or two about china plates, tools or anything vintage, then you could bag yourself a bargain.
Even if you don’t, armed with eBay app you could look up the value of second hand items, with a view to reselling.
(Check auction prices, as “Buy it now” prices can be misleading and not a true reflection what people are paying).
Make sure you aim for a profit margin of at least 100%, and don’t forget to take into account how much an item would cost to post.