I paid about €1.80 for a chinese slate looks same as Bangor blue very thick very natural. Out of interest if your going that way I added and extra 0 to my ridge tile email order and rather than 35 got 350 ft!!!! hmmm still feel daft but have lots left over if you need some. search "reclaimed ridge tiles" on gumtree. There are also pictures of the house with the slates on them,