I won £500 a couple of years back. I also got a small prize at the “ wrong” time of month. Later got letter saying that someone not eligible had got a prize so it had been redrawn hence I had won. We got £50 each this month.
I have had £10 in Premium Bonds since the early 1970s. In 1985 I was absolutely broke and Ernie was an answer to prayer; I won £50!
My husband buys Premium Bonds with the money we save to pay our business tax bill and he’s had several wins - paying more than we would have gained in interest.