I've been watching the Ruger standard, Mark II, and new Mark III's on gunbroker.com and the used guns are selling for more than the new ones. One can buy a new Mark III standard with 4 -3/4 or 6" barrel for under $300. The used mark II's and even some Mark 1's are selling right at or a little more than $300. Are the older guns better than the new model? If so how?