Since you mentioned you like to take shots in low light without a tripod, I thought I'd say a word or two on high ISO capability.
I took a very quick photo just now using my old K5, here in my kitchen. I set the camera at ISO 12800, 1/125 sec and the zoom lens at 80mm, f/8.0.
The first attachment shows a partial crop - just a small part - of the photo, unedited, viewed at 1:2 (ie. 50%) size (I took a screenshot of this while in Lightroom, viewing at 1:2, and dumped it into Paint). You can see there's lots of both colour and luminance noise (particularly in the mottled granite work-surface, the lower part of the bowl, the steel behind the apples - and the apples themselves, in fact). That said, considering the ISO sensitivity, it's not bad - and actually quite good when viewed from 3 - 4 feet away.
The second attachment is the same crop with some *gentle* colour and luminance noise reduction and a little sharpening, all done using Lightroom software. If you get close up to the screen, you can still see noise - I intentionally didn't get rid of it all, in order to preserve some detail. But even at normal screen viewing distance, this is a useable image. I could improve upon it further if I spent a bit of time on it, I'm certain. And when printed out, the level of noise visible in the second image will be negligible if even noticeable.
Yes, I took it on my K5, and I don't have experience of the K-50, but it won't be all that different, that's for sure.
What I'm getting at is, you can shoot at much higher ISO settings than most people think, because (a) software can remove most of the noise very effectively, and (b) no-one viewing your photos will have their face six inches from the screen, looking for noise and other artefacts (well, me and the other folks here might, LOL
).