There was just a 'wanted' post for one. There was a response for $75. Seems fair considering repo '65's are $65 and there aren't repos for 66-7 avail. https://www.v8buick.com/index.php?threads/1967-or-1966-gs-skylark-battery-tray.392393/
My thought is $75-$100 for a nice part that can be sandblasted with no holes in it. Less for one that’s usable but has pinholes etc.
A trove of ‘67 parts? Now you have my full attention. Please block finitebidder and ChiTown67 from seeing your follow-up posts.
Please don't drag this mining operation out like The Legend of Oak Island! Later that afternoon.... Troy
If you don’t mind new/reproduction, CARS Inc (oldbuickparts.com) sells a nice reproduction battery hold down kit that is correct for the ‘67 battery and tray. I bought a couple of them and was pleased.
It is a very nice repo part. Funny thing is that my car was deducted a point or two for having an "aftermarket" battery hold down on it at the 2022 BCA meet. I'm still scratching my head about that one, 'cause it looks just like the original.