Not sure about the laws in Poland, but in the US it really all depends on which State you get divorced in. States with community property laws really are not too bad in divorce, it pretty much is a percentage of what you make for child support and there really is no alimony... there could be spousal support, but typically that support is limited to a time frame which eventually expires case to case. But there are SOME States in the US that are truly horrendous, and judgments are not based on reality. My brother pays $20K per year for alimony to his ex after getting divorced in Connecticut, and that never ends. When that judgement was rendered it was a little less than 1/2 his pay. When he got a promotion and a raise, she drug him back into court to get more, and the courts gave it to her.... and he had to spend more money fighting that on appeal which he won. But he still had to fight.
The thing to remember in the US is that family courts are not courts of law... they are courts of 'equity', fairness is not a factor. My advice to anyone getting a divorce in the US is to get a good lawyer that understands the family law in your State, and to make sure you go in with the understanding that you are going to have to pay something, and make sure that something is what you can really afford and is fair. What happens all too often is that men go into this cases with the attitude that the ex should get nothing, and the woman goes in with the attitude that she is going to take him to the cleaners. If you go in arguing two ends of an extreme, than the woman will ALWAYS come out on top. It's not a negotiation when you get to court, if you are trying to work out a settlement, then fine... argue extremes and find middle ground., but once this goes to trial you do not want the judge to think you are being unreasonable, because it will not work for you. You as a man need to go in starting to for a point that is reasonable... let her be the one asking for everything, and you will come off as someone that wants to be fair.