If starship becomes a real-go-to-orbit rocket, the cost to put this telescopes up there will go down, and they can likely use larger heavier materials to make the telescopes themselves, also reducing the cost a lot
Starship has a 10 meter fairing, so far less folding. It also can lift 5 times the mass of the Ariane 5, which would allow including heavier and tougher materials for the sunscreen (which has already torn once in testing), far more fuel for station keeping to extend its ten year life span by decades.
Even better, Starships 10 meter fairing would allow launch an actual 6.5 meter mirror instead of one built out of 18 smaller segments. The reduction in complexity is immense.
Lastly, Starship makes a JWST style observatory serviceable, even a million miles out at Earths L2 Lagrange point. That in itself makes for a longer life span, and regular upgrades, simplifying design decisions even more.