50 USD or so
You will have to call Ruger.
Semi automatic rifle made by Ruger.
Call Ruger and they will tell you.
Good
Well the mini 14 comes in stainless steel. That is made by Ruger. There is also a Ruger 22 cal. stainless steel rifle.
580 is the newer version of the Mini 14 Ranch, minor engineering changes, improved accuracy, etc.
Ruger has a sn function on their web site.
One could purchase a Ruger Mini 14 Rifle gun at a Wall-Mart store, or using the online Wall-Mart site. One could also purchase a Ruger Mini 14 Rifle gun at a local gun shop.
500 or so
$600 - $1000, depending on specifics.
You rifle appears to have been manufactured in 1983.
$350 to $800, depending on WHICH Mini-14, and condition.