Although this is a good, quality lens from Pentax - it is to all intents and purposes on par with the K20D/K7/K5 kit, standard lens. It is hardly a prime lens?
On the plus side though, it is light, simplistic and totally ideal for 'Snapshots' whether basic landscape or simple, portrait creativity. A nice additon to your camera equipment - but only in elementary terms; as it is a good basic all rounder for a constrained budget. But nevertheless, I guess you could push the boat out a bit - as with the combined use of cheap extension tubes; you should be able to capture some really excellent macro shots in terms of close up photography?
If I was a beginner, I personally would not kick it out of bed; but on the minus side - for someone who already owns an array of prime lenses; then it is a totally, unnecessary purchase?
Pentax please (now owned by Ricoh) wake up and smell the coffee - and produce many more prime lenses as the availabilty out there is rather bleak for Pentax owners. Great cameras, highly underated, but not too many good lenses out there to attach to the body.