When i put countertops, I went to the actual slab warehousess themselves itself. They are kept in this huge cold ass room. 100's of slabs and you go around with a piece of paper writing down the code for each on you like. Some of the warehouses will have prices on them.
I was going for marble at first but then was told that Granite /Marble have a tendency to stain and chip since they are natural stones and more porous.
I went with Quartz because of its ability to be stronger and less staining. Once i made that decision I went to the warehouse in the Quartz section to see how a large slab looks.
So it depends on your criteria.
When removing the wood laminate you can do that to save money like IWEI said. There are screws on the bottom where your cabinet doors are. Just remove those and the possible caulking along the edges. It will save you some cash.
Also you have to make the decision on if you want undermount sinks or overmount. The overmount ones have the lip on them and go over your countertop. People nowadays tend to use the undermount sinks because you can wipe all the water down easily. Then you can tell the countertop people to cut that so it relates to your sink style.
