Please remember that granite is a natural resource and therefore is limited by its natural supply. Certain stones are easily available. Others might be available one day and disappear from the market the next day, particularly the exotic stones. Names also vary depending upon the quarry and vendor.
Granite is one of the oldest and most durable building products available, and will far outlast the building in which it's installed. It has become the material of choice for today's luxury homes and offices because of its enduring beauty, and because no synthetic material can yet compare to its elegance and performance.