I just purchased a foreclosure home and have drain problems

[Pamela Pendley]

I just recently purchased a foreclosure home that has set empty for 3 years.  The drains in the kitchen and laundry room and draining very slowly. Got a plumber to come and snake the drains.  He worked on drains for over 2 hours with the snake but unable to clear drains.  He said the drains have root problems and will need to hire a plumber with a video to see where and condition of cast iron pipes.  Both bathroom sinks, shower, bathtub, and toilet seem to be working fine just kitchen and laundry room have drain problems.  The plumber says the floor may have to be busted (concrete slab) to correct root problem and replace pipes.  My question is has anyone had this problem and what type of costs am I looking at.  Desperately need any advice on this problem. Thanks