Those 20k are a joke. If you sum up housing, medical care and pocket money in Germany you get… a vastly varying number doubly hard to quantify because federation, states, and municipalities all have their different responsibilities, but 1.5k to 2k per month are a good estimate and we didn’t even get to language and integration courses. Some things are cheaper in Poland and Hungary but I very much doubt those 20k would last them more than 18 months or so.
That said, better to lowball that figure than enable them to say that they can’t afford the sum. It’s high enough to have them take a closer look and at least not reject every applicant.