Gas, Water and Electricity

How much roughly would it cost per month for all three in a 3 room apartment in Dusseldorf?

Such things depend a lot on personal habits. Some people like a really warm place in winter although their place is poorly insulated. Or maybe they take a 20 minute daily shower rather than a 5 minute one…   For some basis of comparison I would say that we spend about 150 Euros a month for gas and electricity in our 3 room, 70 square meter apartment in Stuttgart. My wife and I also spend around 200 Euros per year for water. Our apartment is pretty well insulated with brand new windows but in an older building and we are fairly conservative in our usage of utilities. I doubt that there is a huge difference in such costs from city to city...