For purely selfish reasons I hope they get their price. I own a similarly marked gun.
I bought mine a number of years ago at a price on the high end of what you could have any other Webley & Scott 700. It is marked Shot and Regulated by Holland & Holland.
According to an email from Holland Holland my gun was manufactured by Webley & Scott in 1967 for Holland Holland to fill lower market need to get them through tough times. The email also is very specific that mine is not a true Holland & Holland gun but just a gun sold by them.
The one in the ad is definitely a slightly high grade gun than mine. I would say they are shooting for the moon with that price.