I was thinking Switzerland maybe as a backup plan. No taxes.
Switzerland is simply the most beautiful place I've ever seen.
Geneva is not special, but the wee towns around it are magical.
If I were to ever strike it rich I'd be there in a flash.
Been to Monaco too, can't say I enjoyed it tbh, looked nice and all, just thought it was devoid of any soul. Just rampant capitalism.
I dunno mate, best of luck with your decision, but from the way you're talking I think either Germany/Switzerland...or maybe a Mediterranean country would suit your desires better.
Have you thought of Croatia or Bosnia? Price-wise it's quite similar to Poland.