I pay €23.40/month (about $27.50/month) to be able to watch as many movies as I want in all German UCI cinemas. There are no limitations (I think our record is watching five movies in a day) or surcharges. (I think some select newly renovated or built cinemas do take surcharges for certain special seats or cinemas, but I’m not affected in the city I am in.)
That’s definitely worth it for me, considering that I watch a couple hundred movies per year in the cinema. (You need about 3-4 movies/month to easily get above the €23.40.)
The other big chain chain cinema in the city (cinemaxx) offers a similar flat rate (but at a higher price) and this flat rate hasn’t been in place forever, but for at least a couple of years. I would have assumed that you can get something similar everywhere and if not, why not?