Just want to chime in and say I am super happy with my Caesarstone. It looks great (more modern to my eye than a swirly granite) and is flawless after a year of hard use. It was around $70 per square foot, I think, but I bought it through IKEA during their kitchen sale so it was 20% off.

Granite is great in terms of wear for a young family that cooks a lot. That being said, the price range is enormous. Some types (like the ubiquitous Uba Tuba) are inexpensive, while others are as expensive as quartz. If you choose to "hone" the granite, that will also add to the expense. Unusual sizes and additional cut-outs all add to the expense.

Personally, I would go to the granite showroom, where you can look at the different options (they will usually have marble and quartz there, as well). It is incredible how different large slabs look compared to the small samples your contractor may have shown you.

Doesn't the size play into pricing, especially for the natural stones? If you need a really large, uninterrupted slab it's going to cost more because it's harder to find larger, unflawed pieces, and also harder to transport them without breaking them. If you have smaller counters, it's easier to find the right sizes and they can cut down damaged or blemished slabs.

Also, for fun, home depot has a countertop estimator that will give you a rough comparison of different materials. Now, they're prices may not be at all in line with what you're getting via a kitchen contractor, but this is what they list as pricing per square foot:
Quartz: $49-90
Granite: $40-75
Eco: $53-76
Corian: $38-69
Acrylic: $37-69
Laminate: $18-30