Clyde1820

Pre-owned is about the only way I can see getting the quality and reliability that ~$300 used to get in the mid-'80s to mid-'90s, for commonplace MTBs.

Many of them are fairly inexpensive. In a given year, I've often seen a dozen high-quality "vintage" bikes of this sort pop up on CraigsList, PinkBike and the like. They're getting fewer and far between, but they're out there. (Heck, even saw a Rivendell Clem Smith Jr H for $500 up for sale early this year, believe it or not, with decent components, a bike that's every bit the quality of what was commonly ~$300 in the late-'80s.)

In my area, handful of years back, a decent smaller Trek 970 came up for sale. A buddy picked it up, but later sold it to me since it was too darned small for him. Cost me $100. Fully functional, operable, nothing broken, though it clearly needed a cable/brake refresh and repacking/lubing of everything. So that bike was mid-'90s Trek 970 quality for $100, completely usable as-is. But that bike, that weight, that quality of componentry would easily cost north of $800 today, if not $1K.

Rebuilding the bike, I've installed a Chris King BB, a custom wheelset (Velocity, White Industries, DT Swiss), and a re-done drive train. It's well north of $1K, in total. But mine's lighter than most, fits me better (for my purpose, a low-geared upright "city" bike) and has very high-grade components. And it's been a minor labor of love to get it into shape, to get it fitting me properly. Paid more on the wheelset than I probably should have, but it's utterly perfect and bomb-proof. Probably wasn't worth the components, given the age of the frame. But it works "right" and it's geared and fit the way I want it. Custom, for about one-third to one-fourth what a custom bike would cost. And probably far less likely to be noticed if parked amongst a dozen other bikes at the local stop-'n'-rob, as compared to the typical-looking quality "custom" bike.