approximately 1800sqft garage and house done with steel because our 1872 original slate on the house finally gave out in multiple places, and we couldn't find anyone to repair it.
it cost a tick over 12k, which also included an addition to the roof over our deck.
we are very happy with it because it's the type of roof [i forget the name of that style] that has no exposed fasteners that could potentially cause a leak in the future.
it is also one of those "one piece" deals, in that the crew had a machine on site that formed the coil[s] to the exact length and shape needed for each piece.