No argument from me....regarding quality glass. Depending on the use, it tends to be worth the investment. However, one thing to keep in mind. Like other products in this day and age, much depends on marketing. Some expensive scopes are not quite what they seem. Not necessarily junk masquerading as diamonds....I don't mean that. I just mean that everyone should take the various claims made by scope manufacturers with a grain of salt.
An excellent example of this are the Leupold scopes. Leupold, FYI, does NOT manufacture their own glass. They also don't make many other parts that go into their scopes. The glass they get from NIKON - (the Nikkor division, which makes all of Nikon's glass). So, a Leupold scope, despite their extravagant claims, has no better glass in it than a Nikon Monarch. It's the SAME glass.
My only point to make is - don't take everything at face value. Look carefully at the scope/ brand you are considering. Consider all aspects, the clarity, the solidness of construction, the warranty, etc. It is best to ignore most of the advertising hype.