The roasted beans you grind and brew are only the seed of the coffee fruit. The sticky, sugary layer beneath the skin is called the mucilage. In honey processing the skin is removed but the mucilage is left on the seed to dry. It is the sticky texture and the golden amber color of the mucilage reminiscent of honey that led coffee producers to name this method the honey process.
This process is more costly to produce hence the price difference.