Slab floors and plumbing?

[Lynn Harrison]

I'm looking at a house that needs a lot of work, it's older and has a slab floor. I haven't seen the inside yet but I already know it's a mess and the old plumbing will probably have to be replaced. How does one deal with plumbing in a slab? I imagine it's in the slab itself.

Does this always involve a jackhammer? What are the potential costs of having someone else do that? 2 baths & kit. And it is possible or even remotely advisable to instead lay new plumbing and build a floor above it? If so, wooden or cement?