A working line GSD puppy in Germany usually costs between 500 and 1300 Euros. That's less than what you pay in the US.
That really isn't a significant price difference at all. 500-1300 Euro equates to roughly 700-1800 USD.
I'd say the most common price range for working line pups in the US is $1200-$1500. Some as low as $750-$800, a few (*very* few) as high as $2500. But the vast majority fall within the same general price range as in Europe, though a bit toward the higher end of the European range you quoted.
Simple geography and land mass plays a HUGE role. ALL of Europe is roughly the same size as the US. Western Europe, about 1/4 the size. Germany itself, 3.6% the size of the US. Yet there are many, many, many times the number of clubs, trainers, helpers, judges, trials, breeders and dogs in Europe than there are in the US.
All that concentrated in a significantly smaller area impacts supply and demand, which in turn always impacts price. It also significantly impacts the costs that go into breeding. It is much more difficult, time consuming and expensive to train and title a dog in the US than in Europe. It also means many breedings are much more difficult, time consuming and expensive. A breeder living in Germany could go from one side of the country to the other, and even across a couple of countries, in a day's drive. In the US that isn't possible, and if the stud you want to use happens to be on the other side of the country, you have no choice but to fly the bitch back and forth or use AI, and that significantly increases the costs.
Health testing above and beyone hips and elbows is becoming more and more common in the US, and that also increases costs.
Another factor that goes along with the increasing demands for every health test under the sun that exists in the US is the US mindset that requires some form of warranty or guarantee. Some European breeders *may* do that, but reality is most don't. And they certainly don't do it for Joe Public international customer.
Honestly, when it comes to that I think the Europeans are much more reasonable about the whole thing. You're buying a living creature, do your research, make your choice and hope for the best. If things work out, great, but be prepared that they won't. There is nothing that can be guaranteed when dealing with genetics. But most American buyers demand them anyway, and that drives up the price.
So why in the world would you pay so much money for a puppy in the US when you could import a puppy from Germany (including the shipping costs) for the same money?
Price difference isn't really significant. And shipping dogs between the US and Europe has gotten extremely expensive, unless they are flow accompanied as baggage which requires a human to go with them. When you add in paying for shipping a pup from Europe, it is generally going to cost more. Many times quite a bit more.
There is also a very real fear (and it is not necessarily unfounded) that someone buying a dog from Europe is not going to get quality. That the Europeans are going to send their junk. This happens a lot, so that is a legitimate concern. This risk can be reduced of course if the buyer knows the European, or knows someone who does that can help play middle-man and network with breeders in Europe, or can go to Europe to pick out the pup and bring it back. But that isn't feasible for many people, and can significantly increase the cost.
It is much easier for a buyer to research and gather information on a breeder and his/her dogs, and meet the breeder, breeder's dogs and previous dogs from that kennel, when they're in the same country.