I'd be thinking brand new Boyd stocks are worth what you paid for 'em at a gun show.
Milsurp stuff will depend on the condition. I'd judge Stateside prices by what Gunparts wants. Give you an idea at least.
A used G.I. front hand guard in need of care and no metal runs around $30. Refinished doesn't add a lot. Stocks depend on condition, refinished or not and the kind of wood. Birch being less than walnut, but all of 'em are starting at $50ish.
The stuff is listed under U.S. Military on their site.
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