So during the Space Shuttle (and earlier) era I believe the cost of getting payloads to LEO was $20-50k/kg. Currently with Falcon 9 it's gone down to ~$1000/kg. I imagine this will continue to get cheaper with further reuse and Starship.

But we really need to get down to <$10/kg. Thing is, that's entirely achievable. I believe the ultimate future here will be orbital rings [1]. Space elevators get a lot more attention and they really shouldn't because they're a lot less achievable and they require materials we haven't invented yet (to resist the centrifugal force).

Imagine being able to take a cable car into orbit. That's what orbital rings promise and you need little more than copper wire and stainless steel.

Not only would this bootstrap colonization of space but you can simply attach collectors to the ring itself and run the power down a cable to the ground so you don't even need to suffer the power loss from wireless transmission (which, for the record, is a practical method still).

[1]: https://www.youtube.com/watch?v=LMbI6sk-62E