Hard to say without more info. Since it has a 6" barrel it is probably a Mark II. The 2007 Gun Trader's Guide (sorry, that's the newest one I have) says a blued Mark II in good condition is worth $167, Excellent condition is $239 and new in the box condition is $290. There are some other factors to consider, and guns, like anything else, are worth what someone is willing to give for it today.
50-250 usd
Depends on condition, model, barrel, and sights- but anywhere from $100 to $300
Anywhere from $50-$500. Depends on condition, type of barrel, sights, etc.
50-175 US Dollars
75-175
A call to Ruger will get you the answer.
50-500 depending on EXACTLY what you have.
100-350 or so
50-200 usd
Depends on condition, and which version/ barrel. Anywhere from $100 to $500.
100-300 USD or so
$100-250, depending on the condition, type barrel, etc.