One of the most expensive yachts in the world is a gold-plated super-yacht named “History Supreme” worth ~$4.5 billion USD. It’s made up of ~100,000 kilograms of solid gold and platinum plus it contains a wall feature made from the bone of a T-Rex dinosaur. – WTF Fun Facts
Source: https://stuarthughes.com/shop/luxury-yachts/history-supreme/