Welcome to HuntChat JCM. There's a wide range and variety in Europe, mostly because a tag isn't purchased only for one specific type of animal to hunt here, i.e., when hunting you could shoot everything from boar, deer, hare, pheasant, fox, etc, of course they'd all have to be in season.
They are more expensive than a single barrel gun, but if you figure you've got 2 or 3 barrels and one scope, the price is more manageable than say purchasing three separate bolt guns.
Most times when I go hunting by myself, I take a three barrel weapon called a Bockdrilling, 20ga mag over a 30-06 with a hornet barrel to the side of them. It has double triggers and a selector for hornet or '06. There are a large number of combination weapons new and used in Europe, just not so popular and a bit harder to find in the states, partly due to stateside hunting laws. You can check out some of the links below if you want to see what's available from some of the more popular makes, Waidmannsheil, Dom.
BLASER COMBINATION WEAPONS
KRIEGHOFF COMBINATION WEAPONS
MERKEL WEAPONS