Not that high but still worth more then a non bomb site.
Last year i regularly saw A1's going in the $200-$350 range . I snagged one for my K for $150 then spent a few $$ putting in all new parts. NOS part in OH had most of them, I've got the rubber ducky float waiting to go in.
I'd be willing to bet that if you got all the new parts and a used core spent time cleaning and fitting all the parts while keeping track of your time you'd be in the $500 range.
I picked up a rebuilt M-53 with bombsight at a local swapmeet a few years ago for $200.. it was a deal then. Have seen just the bombsights used go for between $100-150 on e-bay.. with no guarantee that they aren't sandblasted out of dimension by someone running without an aircleaner, or just well used beyond usability... might be a good time for an aftermarket product.
When they're running you out of town.. get out in front and make it look like a parade.