For sale ads, gunshops, gunshows, e-gunparts.com
75-1000 USD depending on EXACTLY what you have.
400
100-400 or so
Ruger's web site has sn data.
i see them on auction for around $500 all the time
100-1000 USD or more depending on specifics
Call Ruger and they will tell you. SN info is also on their web site if you can access it.
Ruger Super Blackhawk
Ruger has sn data on their website.
Contact Ruger customer service through their website, with details on caliber, model numer, and serial number.
50-350 USD or so
You need to contact Ruger. You may have a prototype