I'm definitely of the "older is better" club. I have a no dash 4" 686 my late father bought new in Sept. of 1981 (box, all papers, even his original receipt), used it to teach both my sons how to shoot a handgun. It's generally felt the -4 is the pinnacle of the 686 guns but I'd be happy with any of the no dash up to the -4 engineering change. The model number is inside the yoke section of the frame when you open the cylinder if you didn't know. I'd expect to pay around $750+ for a nice example depending if it has the box, documents and tools. You can look at the completed auctions on Gunbroker to see what they've actually sold for but it can also depend on the section of the country.