Am on a water meter, and my bill is about £60-70 per month, this is not even filling the tank, just me the wife and 2 daughters, I will not never ever fill up at home, last resort would be street hydrant, out side my house.
You can buy a tap & key from eBay or somewhere. If you honest john you can even get a license to use hydrants. ( not 100% but I think £240 not sure if that's quarterly or yearly ).
I just use customers taps even if am just doing traditional work there.