I am on a water meter , family of 3
I am DI only and pay around £65 a month , although looking at my last quarterly bill, I think it may be adjusted to about £75 a momnth soon.
I average about 400 ltres a day.
so if I was RO, I would expect to be paying around £150 a month.
I spend about £500 to £600 a year on resin. my tap tds is between 50 and 80
In my last property which I sold 12 years ago I was paying £29 a month and I was RO only
If I was still there , I expect it would now be £45 a month