Ruger has extensive serial number data on their website.
Impossible to answer without the serial number. You can, however, call Ruger or visit their webiste and find out.
100-1000 depending on specifics
You have a .44 Magnum Ruger Super Blackhawk, manufactured in 1978. If you had a question of a different nature, you'll have to clarify.
100-1000+ depending on condition, accessories, etc..
50-500 USD or so
50-1500 usd
Extensive sn data is on Ruger's website. 100-499 or so
100-400 usd or so
400 or so
100-1000 USD or more depending on specifics
100-500 or so