Thank you all for your replies.
There is one good thing about quilting in Poland. It is not a traditional craft here, so there are few people doing it, and even fewer selling their works. I would not even dream to sell my stuff in America. I certainly aim for domestic market and I'm OK with free shipping here. And I don't think anyone expects free international shipping in Eastern Europe.
I intend to start with baby quilts, as they are easier to do neatly enough to sell. I have consulted some friends doing crafts or interior design, and they encouraged me to go on. I have confidence in my stuff, especially that here patchwork quilts are something a bit unusual, especially if they are something more sophisticated than same size squares pieced randomly together.
The bad side of this is that I don't have anyone to advise me on quilt stuff apart from the forum. My knitting, crocheting and embroidering friends are discussing wool etc, producing hoops at social gatherings (pre-pandemic) and I am alone with my machine.
Thankfully, there is this forum to keep my quilting spirits. I am really grateful.