An Uggie for half the money is half the gun. That's why it's half the money.
Markets don't lie.
Actually markets do lie when it comes to the question of quality. Quality has to do with how well something was made, not the price it commands or the speed with which it will be sold on the used market. Those issues are more greatly affected by brand name value and/or collectibility in our little corner of the world.
For real world examples we just have to look at the long term realized auction price valuation tables created by Rocketman here to help with assessing the likely value (selling price) of English and Continental guns. The biggest component of current value is Brand Name. For double guns Branding includes both the actual maker as well as his location (London, Birmingham, Liege, St. Etienne etc)
