I agree a moon base is the logical next step although probably not on the scale you are talking about. Elon Musk recently talked about a moon base as a pre requisite for his planned trips to Mars:

https://www.google.co.uk/amp/s/www.wired.com/story/spacexs-mars-plans-hit-a-pothole-up-next-the-moon/amp

And as everything else he touches seems to turn to gold, let's hope this (and the mars trips) soon become reality!