you're right, prices have risen a lot, but I think to those who collect German helmets ...
In Italy, was sold a German paratrooper helmet at € 12,000 about $ 16,500 ... wow have the value of a large diamond (this is really crazy). 
I have 3 m1 fixed bail, one of a lieutenant, one of MP of the Texas Division and one with the name and serial number of an unlucky soldier who killed in action in France (when I bought it I did not know, I later found this bad info from the serial number...) but I did not spend so much for any of the three! And I would not spend so ever!
Rear seam, fixed bail? 
I have not ever heard and I've never seen anyone either in photo, nor for sale ...
You got some pictures?
I'm so sorry, I meant front seam, swivel bale helmets.
That should teach me not to type things so late at night. 
Erwin
I'm so sorry, I meant front seam, swivel bale helmets.
That should teach me not to type things so late at night.
Erwin
hahaha no problem, indeed I had hoped it was a rare variant so I immediately start looking for one on sale! 
A friend told me that several m1 front seam swivel bail were found, already in houses and under ground in the areas of the Futa Pass!
This partly answers my question, but as I said there is nothing more secure than the memory of a veteran! 