Originally posted by zapp Why buy a $1000 camera if the lens should not cost more than $100.
I can think of a few answers to that. Whether you accept these is up to you.
* Some modern lenses are indeed much better (and worth more) than older kin. Zooms especially have advanced greatly since M42 days. But primes haven't really seen a revolution AFAIK.
* A set of the finest new lenses may be beyond the budgets of many users, and the images they produce may not be hugely 'better' than those from lenses at a fraction of their cost.
* A modern dSLR is rather a complicated beast. A high price is not surprising.
* Sometimes older glass is the only way to get certain lens specifications.
* Older cheaper lenses may give a 'look' that modern glass just doesn't.
* Some older lenses of superb quality are vastly underpriced bargains.
* It's no crime to mix some fine (costly) glass with cheap glass for fun.
* Sometimes we're in situations where we don't want to risk fine lenses.
Others can probably add other reasons. I'll admit to being a cheap bastard who looks for bargain glass. Even so, I have a few lenses that cost in the US$400-1000 range -- and others that *should* have cost that much, but I was lucky. (I lately mistakenly *thought* I was lucky on a pricey lens, but that's another tale.)
Why put cheap lenses on costly cameras? Because we can. Because we want to. Because sometimes it makes the most sense. Because we ain't all rich. Because the voices in our heads tell us to. Whatever. The used lens market isn't going away. My cheap sharp lenses aren't getting duller.