From what I have seen, the prices vary a great deal. Some ask $200, some get in the stratosphere up to $500. For my Aug 42, first M-1 by the way, I obtained one in a trade for an M-14 barrel, which I valued around $200.
It looks to me to be a 12-42 which would make it close for application on from 11/42 to I think 2/43??? When you start saying "1943" it just doesn't have that ring to it.
BTW, my last barrel/receiver from the CMPwas a Spring 42 receiver but a post war barrel. I don't even entertain the chance of getting another early 42 barrel.
Got other fish to fry.