Some nations, like Sweden, limit the number of guns you can own. Last I heard it was six. More could be had with a special permission. I think that has made lower grade guns much less attractive there so the low end market is almost zero. Other nations have somewhat similar restrictions.
I agree with the above reason. In Canada, there are a couple of retailers where the majority of their firearms are lower end guns brought in from Europe by the boat load. Lots of Sauers, Merkels, Simson, Husqvarna, Feg etc. Sometimes you can get a decent deal if you get one when inventory is first "restocked, otherwise many have been rode hard and put away wet.