The Montage Kapalua Bay on Maui has been named the world's fifth-most-expensive hotel with room rates averaging $1,554 a night, according to Luxury-Hotels.com. A recent survey commissioned by the website looked at the average rates for a standard double room during the summer, between June and August 2015. It included properties with at least 15 rooms located in a single building, excluding villas, bungalows and safari camps. The most-expensive hotel by this measure was the Amangiri in Canyon Point,…