Why should I buy a telephoto lens when I can just put a teleconverter on my kit zoom?
That will make your already-slow lens even slower. A 2X converter will make an f/3.55.6 lens, for example, effectively f/711, dim enough to prevent autofocus. And the teleconverters available for kit lenses tend to be of so-so optical quality. Better to put the money toward an inexpensive kit telezoom.
