On Daniel Island the leak is rarely the expensive part. What it soaks usually is.
Irrigation is a common culprit
Homes here have substantial irrigation systems and the landscaping standards to go with them. A leaking irrigation line or a failed backflow preventer shows up as a rising water bill with nothing whatsoever wrong indoors. If your usage has climbed and everything inside looks normal, that is the first place we check.
A test you can do in a minute
Turn off every tap and anything using water, including the irrigation controller, then look at your meter. If it is still moving, water is going somewhere it should not.
Found without opening walls
Listening equipment and thermal imaging narrow a leak to a small area first, so anything we open is small and deliberate. In homes finished to this standard, exploratory holes are the expensive part rather than the plumbing.
Where they turn up here
At fittings and connectors rather than in the pipe itself, since the pipe is modern. Supply lines under sinks, hose bibs, irrigation tie-ins and connections at appliances are the usual suspects.