

This pair is in one holder, from PMG.
However PCGS won't put them together, instead they label them one of two, and two of two.
I agree with SteveInTampa on not understanding why PCGS won't put them together.
But both PMG and PCGS are at least now attributing them as "Production Errors w/ Duplicate Serial Numbers" per Dr. Barts designation, which will be notated as such in his upcoming 5th edition U.S. Currency Errors book, due out this year.
As far as the first pair only going for 6k (7.2k w/fees), in my non expert opinion, I think it was because not many people knew about or understood what they were. I recently went to a coin and currency show in Las Vegas, and visited every Currency Vendor in the show. Not one of these Vendors, (so called experts), had even heard of this topic. They were in awe!
Again, in my non expert opinion, I think once word spreads to the mainstream and the larger world of high end collectors of hard to find items become educated on this topic, and it's legitimized (as you can see, even some here don't think it's an error) by Dr. Bart, prices will increase. Will they hit the Predicted Highs across the internet, maybe not, but if a really low numbered pair is found like the B00000001*, is ever found, then I think..


But what do I know? Nothing, according to my wife.

Wishing you all a wonderful 2022!