I have a 2002 GMC Yukon, and i want to lift it like 2-3 inches how much will it cost?

Google kits for this. You may be better off with just a body lift kit. In the past I had two chevy blazers, and now have a 95 two door tahoe. All were fitted with body lift kits. These trucks were just as good if not better in the mud as trucks with expensive lift kits. The reason why is when playing in the mud, one of the worst things to do is when the bottom of the truck body comes into contact with the wet mud. Why? Its just like if you take two pieces of glass and lay one on top of the other. if they are dry you can pull them apart, but just of few drops of water between them and it is almost impossible to pull them apart. Same thing with the truck body.