1935 USSR 1 Kopek

I am curious, what makes this coin so rare, or unique?

Numista link:  https://en.numista.com/catalogue/pieces6520.html

Not an expert, but it looks like Russia changed the design for their 1 kopek coins during this year. Most of the one kopeks minted in 1935 were of the previous design, but a few of this design were minted as well, followed by a full run of this design in 1936. My best guess, anyway.

Hi

So-called " new type" of 1935  ( without motto ПРОЛЕТАРИИ ВСЕХ СТРАН СОЕДИНЯЙТЕСЬ ) costs much more than  "old" types, but not as unique price.  Just about 30-40 $.
But this piece, as I see has something like dash between  9 and 3, - probably that is a reason if  its  unique  title...

Im not expert, but I dont remember that dash on 1935 kopecks...

yours
David