It is hard to answer your question without knowing the detail. It depends a lot on the total sq ft, the material itself, the thinkness of the material, the edge profile, etc.
Granite is "dirt" cheap, since are a large percentage of the earth crust is granite. But it is costly to cut a block out of a mountain, tansport it, cut into a slab, transport it, polish it, cut sink holes, finish the edge, etc. Any lastly installed in your home. Every company along the way will need to make some money, when it comes to you, it is kind of expensive (that is relative, I have seen other natural stone materials cost a "lot" more)