Hi,
These holsters are being made and sold for a relatively low amount of money (in the 30 - 40 Euro region). Using relatively simple tricks (sticking it in a bucket of water, leaving it outside for a few weeks, attacking it with abbrasive material, etc...) one can easily mask the fact that it's new and then sell it to an unsuspecting person for double the money or even more.
The fact that you bought it cheaply also accounts for it. A real holster, even with a fake SS-marking will fetch much more in Germany as well. These fakers usually target two types of buyers: Unsuspecting (inexperienced) buyers and those that think they can make a quick profit.
Take a look at this one: Look familiar?