Really Ed? You are comparing a best quality London sidelock from Purdey to a Turkish built sidelock with Perugini & Visini stamped on it.
The Perugini & Visini you linked to is not a real P&G sidelock... those start around $30K. That is a Turkish built gun... the same gun is avaiable from Dickinson for $4,000 (clearly, P&G's name adds a premium). That Turkish company also builds that sidelock for Webley & Scott (and they used to make it for Kimber and Hatfield).
So if you have to ask what the difference is between the Kimber Valier and a Purdey Best game gun, then you have a long ways to go. In every regard, the Purdey is a superior gun... not that the Turkish gun is junk... it isnt... but its not a Purdey. Hold them and you'll see.
