Fakery in German militaria is not rampant, it's the norm. On e-bay and at guns shows at least 90% of the German WWII militaria is strait up fake made for the sole purpose of decieving collectors. Only a few online dealers have any sort standards for originality, and even the best ones make mistakes. Many dealers in the business are happy to sell post-war junk to unsuspecting collectors, for example check out Snider and his annoying sight of scams called Sniders Treasures - this guy is a real POS who has made a living scamming hundreds of people with fakes and no shame! Everything is of course sold as 'original'.
Many of the fakes are so advanced that it takes experienced eyes to review even the smallest items. They are faking everything, even German WWII rolls of thread.
The saddest part is many of the so called experienced collectors have been buying bogus WWII German militaria from the pre-internet days before it was discovered just how much of this stuff is actually post war manufactured. You need to be careful who you turn to for advice when starting out as well, if your 'expert' has a bunch of fakes in his collection and believes they are all real you may begin to have a false trust and end up getting duped also. It's a very small crowd who can tell the originals from the advanced post war reproductions, and those who think otherwise are most likely the ones with many fakes in their collections. There are many collectors who have fake items but refuse to accept them as what they are, they have invested so much money to them it has become real to them despite any evidence that suggests otherwise.
Because of all the fakes, it's also getting harder and harder to sell the original items and if you buy from a dealer for top dollar there's a good chance you will never be able to get the money back out of the item when you go to sell. In my opinion, the market for German militaria has become such a minefield with such over-inflated prices for original pieces that it's no longer a good investment.
This is all just my opinion/observations. There are much better things to collect these days then walking into the minefield of German militaria - but if you do than you better have all the latest up to date references on hand, a good visual memory for fine details, a good camera to post items for review online, and a big wallet for when you eventually get burned on some high quality fakes of big ticket items. Everyone who collects German WWII militaria has likely been burned at some point.
-Steve