My hubby is a carpenter...does lots of kitchens. He suggests that you contact either a cabinet maker or a counter top shop. There are small shops that produce only counter tops. You possibly would get a better deal as they may have small pieces they can work with. How big of a surface are you looking at? Do you want new under mounted sinks? Is your cabinets solid enough to hold the weight?
As suggested you can replace your counter tops with a laminate. There are quite a few different manufacturers of laminate and some when done properly can imitate granite quite well. You can have the edges done to replicate those of granite etc.
Also, depending on the size of your counters, you should consider the extra weight.
