It all depends. You know how they say: "Things are only worth what someone else is willing to pay". Any site price calculator is a good starting point to give you an idea of this or that site's worth, but that's pretty much it. Very few buyers are going to go by that (some may though). However, Google Analytics can be your strongest selling point. (How to send an invitation to view your GA stats).
thank you but the question is about the estimate revenues, not the overall site price it seems highly overestimated to me
It's just a wild guess, but from my experience with those types of sites it seems like most estimates (daily, monthly, yearly) are slightly exaggerated.