I am not sure but I personally would not buy anything de-nazified simply as it is not my taste. I buy complete items mainly, unless its things like aircraft wreckage etc.
I think the way i look at these sorts of items is how you want your collection to be, for instance if you buy everything that is mint and not even with a tad bit of rust. I say don't bother with these sorts of things unless you like them, might as well save up for nicer more complete and more valuable ones. Although i have seen some de-nazified items fetch more than real ones!
These items can be very nice for the historical side of things though. Most of the time these items are going to be authentic.