Space hardware costs 10X as much as ground partly because launch is very expensive. When launch is so expensive, it's worthwhile building your satellite to be extremely lightweight, but also extremely robust, since it costs so much to launch a replacement.

Starship has a 9-meter cargo space. Musk recently proposed a successor with twice that diameter. What could we do with a space telescope that size?

The real win though is lunar telescopes. Then it is ground-based. You can build it from raw materials on the moon, which is 45% silica and also has plenty of iron and aluminum. You've got no atmosphere and 1/6 gravity; you can make it huge and get perfect clarity.

This may sound far-fetched but the whole point of SpaceX is to set up permanent human habitation on the moon and Mars, in the fairly near future.