(note: as I mentioned in another comment, it's illegal in Europe to pay interns nothing, but this law is widely flaunted and enforcement is non-existent)
One thing to consider is progression & promotions: expect to change company: if you're hired on the back of an internship will likely net you similarly low wages, which may make %-based pay-rises tricky if you stay in the same company.
This is typically worked around by employers by classifying internships as (purely) educational, but that loophole is predicated on interns not directly contributing to a company's income-generating activities, which is obviously not the case in the majority of instances.
Many do, and it is a losing proposition. Incredibly short-term thinking that just leads to attrition of some of the absolute most valuable hires.
There are articles as recent as February 2022, reporting on calls to make unpaid internships illegal in the EU. Has something happened since then to make that a reality? (I didn't find anything.)
The internships I had in private sector in the US paid me usually a few dollars above minimum wage (and in the last case, about $20 per hour). On the other hand, the summer I interned for my high school I wasn’t paid, but that was acceptable because they were a non-profit and I wanted to have something to do besides sit at home :)
So it really depends on the country the company is based on. Try to look for the legally minimum for internship there
Most internships are not paid and getting experience is more valuable than those 200 - 300 euros.
But don't stay intern too long.
It is however true that many internships are not paid. This practice is illegal in Europe, but it is widely flaunted and enforcement is zero.
You are very wrong about it being illegal! Stop spreading misinformation.
- Unpaid "internships" are technically legal in Europe.
- It is illegal if "an employee is contributing to the workplace" for them to be unpaid
- Most interns are required to contribute to the workplace, which is an illegal use of internships by employers.
In reality, the law allowing unpaid internships is almost certainly a deliberate measure to allow employers to exploit this loophole by placing the burden of enforcement upon interns (since it can be technically legal if they're not contributing, the onus is on the intern to legally challenge their employer. Not only are they less likely to take the financial risk here, it's also somewhat paradoxical as presumably a would-by-intern intending to do that would simply turn down the opportunity (precluding any law-breaking by the employer). There's been calls to make such internships blanket illegal, but it hasn't happened yet.
TL;DR: there is such a thing in theory as a "legal unpaid internship" in the EU, but in practice a large majority of unpaid internships do not fall within the bounds of legal.
Translate it to czech/hungarian/...