JWST is expensive for two reasons. One is the giant heat shield, as it is an infrared telescope. There is no real way around that. Secondly it is the space in t

JWST is expensive for two reasons. One is the giant heat shield, as it is an infrared telescope. There is no real way around that. Secondly it is the space in the rocket, the mirror (and everything else) had to be folded to fit into the rocket. Getting this folding mechanism to reliably unfold was the big challenge - if anything had gone wrong, there would have been no recovery. With its 8m diameter, Starship could house larger telescopes without folding. Considering how cheap a Starship by itself is, the Starship itself could be the permanent housing of a large telescope. It would just need to jettison the tip to expose the telescope inside.