in my search to finish my collection....

i notice 1 auction on ebay out of 12000 some listings a 1964 peice silver dollar proof. now im not 1 to collect proof coins outside of the sets.but being that this is a big key coin event happening i had to have it for my collection of peace dollars.

my question would be. being that the accual coin was never curc. (or none sevived) servived , just emagine working @ the mint when the coins where made. did not 1 person not (yoink) a coin or 2? why did none servive?

what is the proof of this coin worth i can not find in red book.

1964 d pf