Okay, in lieu of calling for an estimate, you need to calculate the square footage of the space you want to convert to granite. Then, research local sources for the price of granite and find out what the cost of installation would be for the calculated area.
Seems to me, it would be more time efficient to have someone who knows about these things give you an up-front estimate. Usually estimates are at no cost to you. At least they are in my area. Or they are a nominal fee. I'm a decorator and have experience with these situations.
In many cases, a homeowner can spin their wheels doing research and checking on pricing and sources in much more time than someone who is experienced in the field. You also have to be sure the person/company performing the work is licensed and bonded. I don't even want to go there if they aren't.
Just my comments from experience.
"As a girl I had zero interest in the stove." - Julia Child
This is real inspiration. Look what Julia became!