Marble Tile Prices What Is The Current Going Price For Granite/marble Tile Installation (average)?

What is the current going price for granite/marble tile installation (average)? - marble tile prices

I have quoted different prices of installers in my area, but found the difference between them is so blatant that I dare not trust the quotes. I was quoted 1.75 to 12.50 per square meter for the installation. I have to finish about 3000 more (floors, walls), both in granite and marble. Why is there such a difference in the price and what is the average price in your area for this service?