"Yeah, yeah," one responded. "He's a part of the family, you know? Poor boy, fairy lights around the column every Christmas!"
Taken aback, John replied: "Oh, okay, so you have actual fairy lights [going around]? Ah, okay..."
The two guests laughed at John's confusion before he added: "Because it's a real statement piece, it is a tricky one to value.
"But I would say easily at auction comfortably £20,000 to £30,000."
The guests gasped in disbelief as one remarked: "That's very nice..."
"Yeah, yeah, I'm very jealous," John admitted before concluding: "Keep wrapping those fairy lights around it!"
Antiques Roadshow airs on Sundays at 8pm on BBC One.