I would be more pragmatic as far as I am concerned:
If the complexity of a certain task(*) is not that high requiring a limited amount of time, then an internship is a very cheap solution (compare 600e/m vs 2500e-3000e for an experienced guy).
Since it is financially attractive for the company, they can offer you 'anything', one should really pay attention on "how such an internship can benefit me from a learning point of view?" "more specifically, Is it in accordance with my career project ?" and so forth, because obviously u dont do it for money.
(*) As an example of task, very often It helps research groups of companies to start a first investigations in the desired domain or project.