Originally posted by Docrwm Apples and Oranges - Primes and Zooms. It's not one or the other. A zoom can be an excellent Zoom but not as good as a Prime at its specific focal length. There are tons of advantages to superzooms, its why they outsell primes. The 18-250 is not a bad zoom, its just not great at some focal lengths - but it's often better than not having a long enough lens and having to try to crop your 15mm Most Excellent Prime Limited when you actually needed 200mm but didn't have it.
I thought I was being clear - I'm saying it might be better to crop a 135mm shot than using a lens with mediocre quality at 250mm.
The mention of primes was only to point out that as you go longer, there comes a point where a quality zoom can become both too heavy and too expensive. For me that point was above 135mm.
Between ~18-135mm, one has many choices, and can choose medium priced zooms with above average quality, along with various cheap or expensive options. Longer than that (and to some extent, wider than that) the options become more limited - i.e. you have to choose between cheap, expensive, and really expensive!