In Argentina, public universities are totally free. You do a year of CBS (Ciclo Basico Superior), which means Superior Basic Cycle, which are just the base subjects, and from there, you pick your branch and start.
Of course, you have private universities which are paid in which you don't need to do the CBS and you pick the branch right away but the rest is pretty much equal. Maybe you get better classes because not many people go to public universities here so there's less students per teacher and be it private, the university can buy stuff to do more practical classes than theoretical unlike in the public where you have few practical classes due to budgets.
You can drop out anytime and come back in anytime. The onlything that matters in our universities are your exams. You have theoretical and practical exams. The scoring rank is from 0-10. You pass with a 7 and it is VERY hard to get even a 4 in our faculties because you're taught and taught and taught, you need to get on your ass and study to get close to a 7. You do have make-up tests.
If you fail, you have to retake the course the following year to stay on track and avoid "equivalents" which are basically tests that test you on everything learnt in the past courses. You'd need to take one of those to get back into the same course level.
Your degree is very valuable because it's hard to get one in the public universities but they're totally free and you have lots of free tools at your disposal in case you need any help. You can also do residence in an official building of your branch to help out and learn better. Ex: you're studying medicine. You can do residence in a hospital and get to be around the docs while they do their real work and you learn. Our best branches are medicine. Be it human or animal.
You leave the univercity with a bachelor's degree and from there, you can master it to get a profesor's degree and you can master that to get a doctorate's. (Note that I am doing brute translation here and the actual names may vary)