To say the thruth many Polish games can be called crap. But still there are good ones like Doman and Franko you mentioned or Funturatum, Kupiec, Legion, Lost in Mine, Pole Walki, Teenagent.
I think that thoose games were only sold in Poland. But how expensive were thoose titles?
I depends on a game, but if you want to calculate it to euro then these games costed between 6 and 15 euro. But remember it was almost 10 years ago and only few % of games people played were originals. In fact there was no such thing as illegal software ;-)
If you're interested you can still buy Polish games on auctions.