Quote Originally Posted by sonix
If you just buying prime lens as a hobby, at least for me it's not really a good idea. How willing are you to back and forward to frame your object nicely?

Anyway just a thought....
Prime lenses have their uses too. They are generally very sharp, fast focusing, and certain ones cost less than say, a zoom lens of the same range. The popular 50mm f1.8 is an example of a good, cheap yet fast, sharp and lightweight lens. Also, prime lenses can be coupled with teleconverters resulting in little image quality degradation, due to their simpler construction (less elements to interfere with the light path). Zoom lenses fare poorer with TCs due to their more complex design.

That said, both primes and zooms has its own uses. Some people prefer zooms due to their flexibility and ability to compose on the spot without moving back or forth, especially useful in tight situations. Others swear by primes due to the reasons above. Nothing wrong in hobbyist/amateurs investing in prime lenses, depends much on your shooting style and what you shoot.