I don't know about best, but I bought a pair of cufflinks at a carboot for £3, Vera asked me why, on the grounds I've got plenty. When we'd moved away from the stall I showed them to her. The were gold. I sold them at auction and they sold for £95.
I think the best one was a round occasional table I bought in a junk shop for a tenner, turned out to be 18th century Chinese. It sold at auction for £550.
Food bargain, a very large joint of beef for £1 in the
co-op. I didn't believe it so asked an assistant if it was ok.
It had been marked down a few times.
So large I froze half of it.
Morning, Gmum......I suppose the best bought and resold was a car I bought for £50 then sold a few months later for the £100 I needed as the deposit on my first house.....x