Could you tell me, where exactly is the most costly region in Hong Kong? Is it the bustling Central district, known for its towering skyscrapers and exclusive shopping malls? Or perhaps it's the serene and picturesque Repulse Bay, renowned for its luxury residences and breathtaking views of the South China Sea? Alternatively, are we looking at the vibrant Causeway Bay, renowned for its high-end retail therapy and vibrant nightlife? I'm intrigued to know which area in this vibrant metropolis commands the highest prices.