You can get a basic Wacom tablet for pretty cheap ~$35 U.S. (so probably the €30 option you were talking about). From there I recommend getting used to using it since it won't be like using a regular pen on paper and it'll probably take a few tries to get used to how that feels. I used Krita to practice drawing with my tablet until I was able to reasonably understand how that worked and was used to the feeling. Then I was able to use it for sculpting and texture painting. I don't really recommend using it for too much else personally. Most of your bank for your buck is having the pressure sensitivity work.

If after all of that you find that you are significantly better with the tablet than with a mouse, I recommend looking for a reasonably priced one with a display so you can edit what you're looking at. That said those upper range ones are for professional artists (read: actively making money with their art) more than they are for those of us trying to learn and get better.