In those long-ago days, vaporware and unobtanium were just a gleam in eyes of engineering futurists.
Today, the space elevator is hardly closer to being a reality than it was when it was first envisioned but all that’s holding it back is..vaporware and unobtanium.
The first problem is materials. I think we’re much more likely to have the ever-elusive “propulsion breakthrough” that’s always presented as the limiting factor for affordable space access.
One individual has estimated it would cost about $20 billion to research, develop, and build a space elevator. I’d offer such estimates can be dismissed out of hand: how can you come up with an estimate that regards technologies, materials, and construction methods that don’t exist?