These are the last of the trade ins, I think we'll see. The odd security company that is holding on to older S&W revolvers and getting the last drop of use out of them are the ones that are trading them off now. No PD I know of issues revolvers anymore, I doubt there are any. A few security companies still carry 64-7's and -8's because they are still the same price as Glocks and some states mandate rent-a-cop companies to carry .38 revolvers with no more than a 7 round capacity, i.e. the reason S&W probably still makes 64's. I heard from a guard on another forum who carries a 686+ loaded with .38+p only, but these cost more than 64's so this is rare.
The "real" era of the trade ins, at least that I saw, was the early to late 90's when PD's and security companies really dumped a lot of wheelguns and went to autos almost en-masse. I recall seeing 10's, 64's, 65's, 66's, etc. for under $100 in that kind of well used shape at gun shows in the late 90's. And I mean tables full of them not just onesies and twosies. If I had been 21 at the time and had the money I would have bought dozens of them.
I don't see beater Model 10's going up in price much, there were many, many made and these are not collectible in this condition. A lot of the J&G $180 Model 10's, I would bet, are now sitting on gun show and gun shop racks marked at $300 and probably selling.