What's considered a medium town in Poland? I was checking out housing in my dad's hometown in Serbia, and it's like a shitty agricultural town pretty far from anything notable with a population of ~12,000 and a place was still like $40,000-50,000CAD.
Well, it's probable that no new houses are being built in the place where you were looking for a home. The local community is probably strong too, so not many people are moving away.
I can tell about Novi Sad (250k people, nice university, nice city center etc.), you can indeed get a livable flat for one or two people without kids for anywhere between 20k-35k euro. Though there are still some downsides to living in Serbia.
However, I was born and I still do live here as a freelance software developer (maybe at 30 hours/week, including time for learning new stuff), mostly Rails, nothing fancy, and I can tell that with a family of 4 I'm still saving 75% of my after tax income. Without trying hard to save money. That's what's keeping me from moving westward.