As for the Leupold, I would think that $300 would be as much as I would pay for one. I do see them advertised for a whole lot more than that though. I paid $300 for one just like that only in 36 Power. I say $300 because you can buy a new Bushnell 4200 6-24 scope for not much more than $300, and it has excellent glass too.
The Unertl is a collectors item, and prices are varied. You might end up paying $600, or more for that scope. Collectors dictate prices on these old scopes.. I paid $900 for a 1 1/2", 24 power Unertl Target scope 5 years ago.
Martyn