They can go anywhere from $500 to $1000, depending on a number of different things. Ruger made a few different models of the Mini-14, and changes to models over the course of its production life (which started in 1973).
$600 - $1000, depending on specifics.
100-500 USD depending on specifics
The Ruger website, under Customer Service, has a downloadable owners manual for your Mini 14.
580 is the newer version of the Mini 14 Ranch, minor engineering changes, improved accuracy, etc.
$350 to $800, depending on WHICH Mini-14, and condition.
If you go to Ruger's website you can download the manual for your mini 14 for free. It tells how to disassemble your gun in the manual.
250-425 USD
You can contact Ruger's customer service to find out.
100-435 USD
It says it can on Ruger's website.
You will have to call Ruger.