I just find the K1000 over-rated. It's hair shirted minimalism for the sake of it.
Pentax had already offered the KM, which had a self timer and DOF preview. The K1000 borrowed heavily from this model but simply didn't bother with two very useful additions.
The KX is much, much better than either. The metering is more accurate, it has MLU, and the viewfinder tells you more. I just wish I'd known they existed in the 1990s when I bought a K1000 as it was the "beginner" SLR (in a pre-Internet age all I had to go on were magazines, which didn't often publish a list of old cameras with their relative features). The KX is a tough, completely manual camera but just makes your life a little bit simpler.
I regularly see KXs (and even K2s) for the same money or less than some K1000s. Unless you're a collector then why bother with a K1000?