Chris Cullen from Bozeat made an appearance on national television last week, when the Punch and Judy man was shown buying an unusual paperweight depicting the warring puppets.
Mr Cullen, of the Banana Brain Fun Shows, has been putting on Punch and Judy shows for about 30 years.
He made an appearance on BBC 2 show Put Your Money Where Your Mouth Is on Friday.
Mr Cullen said: “Two antiques experts play against each other, they buy items to auction and sell at car boot sales, they have to sell them on and whoever makes the most profit wins.
“Kate Bateman, an antiques expert from Oundle, came to Daventry Country Park in June, where I was doing a show. I bought the paperweight for £70, then I found out she bought it for £10 off a car boot sale.”
Mr Cullen said despite the difference in prices paid, he had paid less than he could have, as he had been prepared to pay up to £80 for the item.