Its up to you to control your own LBA.
I know cause I had really bad LBA.
Trying will let you want to buy it at 1st, only after you try awhile then you will realise you may not want/need it.
I started from Kx, to Kr to K5.
Started with 18-55 and 55-200, realise should try longer range, sold 55-200 for 55-300.
Newbies usually start with zooms, so did I.
Realise benefits of F2.8, bought Tamron 17-50 and 70-200.
They are really good, but zoom creeps, weight and LBA is a problem.
In the end sold both for Da*16-50 and Da*50-135.
Then bought Pentax Fisheye, sold it soon after to fund Sigma 8-16 to get the best of both worlds (wide/fisheye effect) imo.
Realised the quality of Pentax's primes, bought 15, 31, 77.
Wanna try F1.4, bought Sigma 50.
In the end sold 15 and 77 as I seldom use that focal length.
lol I took the expensive route, buy and try.
Now Im just left with the essential ones that I use alot.
Its Pentax, thus you may not be able to try all the lenses in shops locally, only through owners.
Unless your overseas or you know the salesmen well. ;p
So I would highly suggest you to hangout with the Pentax family here in their outings instead and try the lenses.
Dont be like me, I anti-social hahaha. Kidding. :bsmilie:
Try and hopefully you get the antidote to cure your LBA knowing the lens may not suit you, instead of trying and poisoned in wanting to buy all.
I do get alot of info by reading the advice given by the pros here and in Pentax forums though.
Also see Flickr for the samples of images taken by lens you wanna get.
but it took 2 long years to get to that 'zen' stage of not feeling the lust for more lenses.
It took about the same for myself as well.
Im done, unless they come up with a new 16-50, or maybe I should try a macro. :bsmilie::bsmilie:
In the end I also agree with detritus, "save up and buy THAT one".