For my 4rm flat too bad the main toilet and mbr's toilet is not "back to back" so need extra long copper piping running from service yard to mbr then to bedroom's toilet. My plumber quoted me for $750 inclusive of two ponzzi or rozzi mixers, saw homefix selling at $80 per piece but i never asked them. First order from citygas is a estimated a month ago and plumber came in action 2 weeks later. During the installation my house is like war zone, so dusty and the noise is very lenghty!, I felt like stepping on a coat of talcum powder in whole house haha. I have to say $288 + $750 is very expensive for me but if you think GREEN and ultimately reducing the utility bill this it is. Next project is the LED lighting in my nest If anyone wanna ask more please pm me, my location is @ gangsa rd beside Mayspring Condo. Notice the small pipe into wall is where the mbr is, to the right is main toilet. Water source is now shared with my washing machine.