Posted by TomC-(MD) on December 16, 1999 at 16:28:16:
Entire replacement of a slate roof is very expensive. About 4 times the cost of compostition shingles.
On the flip side, a slate root has a life expectancy of over 100 years, compared to 25 or so for composition. If there are a few broken slate tiles, new ones can be installed. They add a nice look to the house that many buyers like. In fact, I am closing on a house Dec 30th that has a slate roof.