I don't think I'll add something new here, but my own experience and observations.
Actually, it was one of the last film cameras in production to be "tanked". It was not overpriced for new RF camera and it was sold successfully during rangefinders renaissance which appeared while film shooting was still relevant with mass market. As of now the rangefinder lust is partially migrated to digital platform. With used Cosina-Epson made RFs and used Leica RFs on acceptable price range and elite pricing of new digital Leicas RF. Plus fake and cheap RF like mimics from Fuji. X series.
On remaining market niche for film RF cameras no shortage of used cameras is observed.
Why used Leica M cameras are as popular as new or used Bessa? As of now where no huge difference in the price between M and B. I stated with like new Bessa R. After one year of travel, daily use it was loosing paint, rubber exterior looks like crap and shutter blades started to show some wear. It was no local service available and local official representative ignored request for spare parts. I went with like new Bessa L, but it has constantly jumping shutter. I decided to try Bessa T, it came unused, LN and after second film it has VF mount loose. Now you know why I would never try something like 3M. Heck, if only they could balance them right, instead of placing lugs in the place where it is forcing camera to turn up....
I went with used M4-2. No batteries to be worry about, shutter sound is the kiss and it worn out nicely and slow. It is all metal. Handling of it next to sexual touching!
. And it is supported locally and by known repair shops which aren't at another continent of origin. Leica M is classic approach, which is matching classic RF concept. Recently I paid $725 for shipped M4-P in user condition. It has slightly fogged VF, which isn't as bad as it needs cleaning right away. One second speed was off. I left it at local camera store for one hour and speed was fixed at no cost. So, with no parts, no service, no repair manuals for Bessas I was not confident of buying it new at $700 price tag. But buying used Leica M for same price was not a big deal. Once you'll get film M into you hands you will realise why they are still number one for those who want RF camera for daily use and years to come.
Cheers, Ko.