But the Steiff toy has now been valued at between £4,000 and £6,000 and will be sold by Derbyshire-based Hansons Auctioneers on August 16.
The second toy, a pre-Second World War Chad Valley bear, is estimated to fetch between £80 and £120.
Ms Davies said: “I just had a feeling – a gut feeling.
“I thought he looked like a Steiff bear, a make which can be valuable.
The hunch was strong enough for the pair to part with the largest amount of cash they had ever spent at a car boot.
Mr Johns said: “We’ve been going to the Monmouth car boot sale every Saturday for years but we’ve never found anything as valuable as this.