Chrome Hearts sunglasses are expensive because they are made from high quality materials and craftsmanship. The frames are made of stainless steel, titanium, or sterling silver, and the lenses are made of high quality optical glass. Chrome Hearts also uses advanced technology to create their signature designs, including intricate engravings and unique shapes. Additionally, the brand is well-known for its unique style and luxurious aesthetic. All of these factors combined make Chrome Hearts sunglasses some of the most expensive on the market.