When I was in the market for a Spanish sxs I checked out William Larkin Moore. Their prices were such that I could fly to Spain and order the gun there for about the same money which is what I did. I don't know if the same can be said today but judging by the prices of some of their guns I'd be surprise if it weren't still the case.Wm. Larkin Moore is a good place to handle guns to see what you like, and also what you don`t like. It is a premium price shop, so I find the prices high, but I am a patient shopper when it comes to good double guns. I would not miss it if I was in the area.
The English gun that was shown looks nice but I'm wary about English guns sold outside of the UK and wouldn't touch one unless signed off by an independent gunsmith. Too often English guns have been altered, are out of proof and couldn't be sold in the UK. If I wanted a used English gun I'd go to England to buy it. Here's a good site for comparison.
https://www.guntrader.uk/Guns-For-Sale/