Price may be kind of a hard thing to pin down. They always seem to be worth quite a bit more to the guy selling it than it is to the guys who print the Blue Book.
Not to get into trouble with the copyright stuff, they may, or may not, list for just a tad over $474.99 for one in just a tad over 99.99% condition.
Aside from cosmetics, you'll want to see no binding in the action (both single and double). Look for scrape marks on the sides of the hammer- minor may be nothing, but serious ones could mean goobered up inside pins. As you cycle the action, hold the weapon sideways where you can watch the cylinder gap as you cycle it 6x. If the gap changes- you'll have a bent ejector rod, probably from hollywood wrist flicking to close it. The cylinder should have no more than a barely perceivable back and forth movement. I don't know how to describe lockup ratation, there will be some, but it will be minimal. You should not be able to push the hammer forward with reasonable forward pressure (5-8lbs). Check this by cocking the revolver, keep finger off of trigger, and use thumb to try to push the hammer spur forward. The sideplate screws shouldn't be boogered, nor the main spring tension screw which should be all the way in. And the firing pin should be nice and rounded and have some wobble to it from where it is riveted into the hammer.
OK, now the dashes. Those are marked production changes. From 1970 to when yours was made, the gas ring was moved from the yoke to the cylinder in 1977 (-1). In 1982, they eliminated the cylinder counterbore and the pin that prevented barrel ratation and the cylinder length was changed to 1.62" (-2). In 1986, it got a new style of yoke retention system, new radius stud, hammer nose bushing, and a floating hand (-3). About 1994, hogue grips came along as an option, the extractor got itself changed, and a new sight leaf showed up. They also started drilling and tapping the frame for opticals I guess (-4). In 1998, the frame changed by doing away with the cylinder stop stud, serrated tangs, and they went with a MIM hammer with a frame mounted floating firing pin, and some of the internals changed with the MIM production, and I think they went with a smooth trigger face (-5). Yours should not have the hillary hole (internal lock). Wording and approximates were changed to protect and prevent copyrighted material which may or may not have come from a reliable source.
Once you get into Smiths, you might want to dig around in the net for 3rd Edition of Standard Catalog of Smith & Wesson, which is copyrighted matterial and should not be misused or reproduced without written consent or acknowledgement.