The current digital Leica M10-P sells for $7995. The Leica M3 that cost $456 in 1958 is $4035 in 2019 dollars when adjusted for inflation. A couple of things to note:
1. With the M3 one would have to spend lots of money for film, processing, taxes, etc. over time. With digital there is no incremental cost to taking photos (other than the minuscule amount spent storing them on digital media such as hard disks) so the higher digital camera price is not particularly important, IMO. One does need some sort of computer, but pretty much anyone even reading my post has one of those already. Doesn't even have to be all that powerful a computer if shooting jpegs or doing straightforward raw processing. Lots of software doesn't require very high end hardware to run well. Lightroom and some others do though need pretty good hardware.
2. There are lots of 60+ year old M3 bodies still in use. How many think that an M10-P will still be usable 60+ years from now?
Even if it still works properly (pretty unlikely) the chances of memory cards, batteries, etc. still being available then for it is pretty much nil. Also, digital file formats may have changed so much that most or all software can no longer handle the files it produces and old software may not run on whatever people are using in 2080. There is an excellent chance though that lots of M3 cameras will still be working...as long as there is film and processing chemicals still easily available.