Okay.... now that I have the time I can put in my worthless wooden nickel of an opinion in.
1. 2020 has been the craziest panic year ever. Between the fears of social breakdown first due to the pandemic followed by race issues and topped off like a cherry on a sunday, the election. Folks are buying up everything that isn't nailed down. And if it is nailed down, they're paying premium for the crowbar to pry it off the base.
2. The supply of police surplus S&W autos is drying up. There were only so many made and only so many were purchased by government agencies. Only so many are surplused and sold versus sent to captain crunch. With an ever increasing demand for guns, both on the collector market and the general market and a ever decreasing supply. Prices only go one way and that's up.
3. People are starting to wise up and see them for what they are. For a very long time, people listened to gun writers like Jeff Cooper calling DA/SA guns "crunchenticker", bad mouthing S&W due to the higher price associated with the gun due to production costs, etc... S&W Autos have become popular because they were cheap surplus guns and when they're cheap surplus, people that are cheap buy them and then start to realize and go ssy things like "damn, this is a good gun. If this were made today it'd be easily over a grand."