does it make the noise when shut off or when turned on?
is it after the water runs for a second or two ?
and what fixture does it make the noise at and witch ones does it no?
and last do you have a water heater or a coilin the boiler
lets fix your plumbing first , then we will talk money lol
ok lets plumb
do you have a pressure reducing valve on your water main or a double check valve . some times thease devices will make this noise throught the house when water is used usualy when any water is used but i have seen it when water goes into the heater and through a few valve or through heat traps ( special nipples on water heaters ) the pressure get reduced just enough to cause a bouncing of the diphram or washer in thease items
lol not realy
but in your meter pit you have a meter and thats it do you see another device that looks big and brass like with ports on it
i tell you what if i am gone i will back tomarow after 5:00 if you can wait if not any other expert can help if you wish
enjoy your diner