They were made in limited numbers during the production of the Ruger Mark I and II series, and are of some interest to the advanced ruger collector. They will only bring a premium if they are mint in the box with all the original paperwork, otherwise they are not worth much more than the existing models.
50-150 USD or so
100-300 USD
1/10 IIRC
50-175 or so
50-500 USD depending on specifics
Depends on condition, and which version/ barrel. Anywhere from $100 to $500.
100-400
75-275
$350-$500, depending on the exact version, and the condition. The rifle is a Number 1, not Mark 1. Only Ruger pistols are Marks.
200-400 USD
$250-$500, depending on the EXACT model and condition.
$150-$250, depending on condition, barrel, sights, etc.