I haven't bought a single book connected with my studies throughtout three years. I've got everything I need in my institute library. It's enough to spend some time in the reading room. However, I have to spend some 30-40 zł a month for various photocopies.
, some penalty exams
Why do you assume every students needs to re-take exams?! If you f**ck around all year and remember that you're a student 3 days before the exam - then, yes, you have to pay. But you can study regularly and pass everything on zero and first terms.
and obviously for accommodation, food etc.
You pay for food and accommodation whatever you do, not only when you study.
What's more, if you've got a high średnia (something like GPA), you get a scholarship. In my uni it varies from 250 to 400 zł, depending on your średnia. You can also give private lessons in the subject you study or foreign languages (25-35 zł per hour) and get some odd jobs while you're a full-time student, without the fear that you will be overwhelmed with too much activities.
The conclusion is: the lazier you are, the more you have to pay.