That model is a "grail " gun for many and as a per centage of the dwindling numbers of pre-lock S&W's available this one is in the lower numbers comparatively.
Yes, the market (in general) has softened. Can you expect to find pre-lock S&W's at prices less than even when the current administration came in ? Always the possibility that the blind hog will find an acorn once in a while, but if it's something you want and it's relatively scarce on the market (as opposed to say, model 10's or 29's) the don't hold your breath waiting for a 99% specimen to fall into your lap for a price that some folks will pay for pristine K frame in the box with all the case candy.
The market has softened in general, but quality hard to find desirable S&W's are still selling at pretty good prices, just not as fast as a year ago and not to people who had more money than sense who panicked and bought everything in sight over the last two years. That train is staged up back at the station waiting for the next sensationalistic headline about shortages or bad legislation.
Personally, I'm not seeing a big drop in price on the kind of thing your talking about, just more folks willing to sell them that are facing hard economic times or finding their panic has subsided and they'd rather tie the money up in something else. Like everyone else, I love to run across the occasional poor decision maker who bought a model 58 last year (or whatever) for top dollar and is now needing cash so bad he's willing to take a beating. It happens, but not often to me where I can take advantage of their fire sale. That falls into the category of the widow selling her late hubby's gun at a yard sale insisting she gets the full price on the receipt tucked in the box when he bought it 40 years ago . . . .
For a 99% specimen as you described there may be better deals out there, but waiting to find such and counting on it may turn into years and never materialize. Try this, put an ad in the WTB section asking for at least a 99% condition model 58 for $650 and see how many responses you get . . . we'll wait :D