I am in the process of purchasing granite countertops for my kitchen.
I've found a local fabricator who purchases slabs, cuts, and installs them. The same style countertop is going to save me about $1800 over the quotes I recently got at Home Depot.
Our cost is $4015, and we'll have about 40 square feet of slab left to do another project with. We would save on this amount had anyone else having their kitchen done picked the same style and needed a portion of our second slab.
We have about 66 square feet. Here's a photo of my kitchen at Christmastime...and is the BEFORE photo.
In addition to adding countertops, I'm going to be replacing cabinet pulls, replacing the old cooktop with a gas downdraft model and adding a wine cooler. We live in a neighborhood that is high-end for our area and purchased our house for substantially less than others in the neighborhood. It just needed some upgrades and love, which we're trying to do right now.
So, I think if I had to judge whether it's worth it or not, I would look on one of the realtor sites to see what other houses in my area have and what buyers are expecting out of a home in your price range.
If you're planning on staying for years and years, do what makes you happy! You have to deal with it every day...and if you don't like it, you'll never be really happy there.