It ain't 1957, it's a Super Blackhawk sight, and they haven't made them in quite a while. Heck, that sight is older than my son!
Parts ain't cheap when they are in demand for good ones.
And, Hawkeyes used to sit on dealers shelves too,, for under $100. Now they command around the $2000 mark.
Times & prices do change!
I bought one a couple years ago from another forum member. Fit right nice on my OM .45. Wanted to jump on this one but my wallet developed a pucker hold on what little cash I had and wouldn't let me.
If you want the parts you gotta pay the tariff.
Besides ........ it's only money.