If you care about money, it is not worth it. But you probably should not have done a PhD either.
If you care about science, a postdoc is ABSOLUTELY GREAT! You will never in your scientific carreer have the opportunity to do so much work by yourself. As soon as you become a lecturer/professor/whatever equivalent your country has you will have to write grant proposals, go to conferences, teach, etc. all getting in the way of science. Given the choice (read: if I can afford it) I take a postdoc position any day above any other academic place.