Assertion: reflecting telescope's mirror | /r/HasProperty | cheaper to make
Facets:
value: a lot
type: DEGREE
Source sentences:
text: Once size nears 100mm, when compared to its refractor counterpart, a reflector is more cost-efficient because mirrors are cheaper to make than lenses
text: Newtonian Telescopes have a big advantage over telescopes with lenses such as refractors and Cassegrain telescopes, as mirrors are a lot cheaper to make than lenses.