In Slovenia you can stay in huts.
https://en.pzs.si/koce.php

The cost is from 20 eur/night for non members.
The network is dense enough, but you need to make sure the hut is open.

If you wild camp outside national park, populated areas and practice leave no trace policy nobody won't fine you. A lot of them don't like wild campers, because they haven't camped out in wild even once in all their lives(closed-minded) and that is it.