[raymo]

You are quite right, astro gear does indeed have a much greater lifespan;
there are many mounts and some scopes in use out there 30-40yrs old, and
a smaller number older than that. Accessories similarly have a long production life, and there is a thriving classifieds section here too.
Bintel will be short of stock because of covid, as are all other importers of
astro gear.
Regarding an equatorial wedge for your SCT, I'm assuming that you want to do some photography. SCTs are the worst possible choice for
beginners unless you want high magnification for planetary/ lunar work. They are very slow photographically, necessitating long exposures, and due to their great focal length are much harder to guide accurately, and also have a narrow field of view so that only parts of larger targets can be photographed at any one time.
raymo