Plumbing and Piping - Types of Plumbing - I'm a little lost!

I've heard old homes use galvanized steel for their supply lines, which is, I'm sure, what we have. The water pressure isn't great either, which I heard is probably because the pipes are corroding and causing backup. We're not ready to invest the money to have those replaced, but does it pose a health risk? My dad does construction and said PVC pipe is used now. But you don't use PVC to supply water to the actual house, do you? That poses a health risk, right? So what kind of plumbing should be installed for flow into the house?

No health risk,

CPVC or copper is used inside the house, pvc water pipe can be used from meter to the house,

Any idea what sort of price range I would be looking at to have plumbing replaced for a pier & beam foundation, 2 bedroom, 1.5 bath house...approx. 1000 sq.ft.? I'm in California.

And thanks for the info!!

Call for estimates, no possible way to tell you what it will cost on here. Not there to look at the project.

Here in Atlanta, that type of job would run somewhere between 1500 and 2000 bucks if it is all on one floor.... But as P2K says, the prices can vary wildly in different areas... And the type of material will cause some difference in price... Copper being the most expensive of the three materials mentioned...