DSLRs are insane value right now as everyone jumps to mirrorless. Which is just silly fashion, IMHO. (Or, if you're like me and prefer optical viewfinders, kind of important). I'm jazzed that people are abandoning things like cds, physical books, and DSLRs - more for me. An aside: I can't believe people have so quickly gone from "geez should I even shop online" to "hey lets put my whole live online and burn the physical copies". That happened in the last 20 years. No engineer or risk analyst in the world could say this is a good idea. Computers, software, and the internet need to be stable for 100+ years to be relied on to that degree, IMHO.

Oh totally! I won't deny that mirrorless has some advantages, but it hasn't devalued dslr to the extent people think it has.

If you start from scratch, used mirrorless bodies are good value as well. Lenses tend to be on rather expensive so. I consider myself lucky so, old screw drive AF Nikkor lenses don't auto-focus on mirrorless, and thus rather cheap atm. The old AI-s lenses on the other hand are manual focus anyway, and since they are optically really good, are becoming more expensive now.

canon is also a great choice because the ef mount is larger than most other dslr and it can fit pretty much every dslr lens that exists (vintage and new) without the need for an expense adapter that has optical elements. You can even 3d print them

Between Nikon and Canon, the choice comes down to taste and personal preferences. Both are equally good. Same goes for mirrorless between Nikon, Canon, Sony, Fujifilm or Panasonic. Whatever you pick, it is not wrong or a mistake.