Since I am from Germany and our banking and tax system is quite similar to the Austrian, I totally agree with Armin in each single point! Maybe not exactly wha

Since I am from Germany and our banking and tax system is quite similar to the Austrian, I totally agree with Armin in each single point! Maybe not exactly what Armin described as a solution - but did you already check Flattr (https://flattr.com/ https://flattr.com/)? This also might work for supporting OpenSource projects.