I'm standing in same situation, especialy, that about month ago my K50 has broken and repairing it will cost much more, than it is worth.
So far i bought used K5 and i'm waiting.
I would buy KP if it has GPS. But now i'm waiting for K3 successor and collecting money.
If it will not be so good, i can still buy KP, or even jump the ship ang buy something non-pentax, especially, that lately i'm starting to play with video.
But for me, 100% satisfying K3 successor would be KP + GPS + a little bit better video. I know i will not get tilt screen probably, and that's not so good, but i can live without it. BUT GPS is now must-have for me as person who travels a lot (mostly locally, but still) and geotagging my images semi-manualy is way too much work right now.
So, if KP dos what you need, go for it, it's getting quite cheap lately. If not, collect money and wait, you can always buy KP later, it will be on marke for few years i think
And i'm sure you'll find some way to spend extra money