In a small bowl, mix white sugar with salt until blended, and set aside. Stir the honey, brown sugar, and water together in a large pan over medium-low heat until the mixture boils and the sugar crystals have dissolved. Cook the syrup until thickened and bubbling, 10 to 15 minutes. Stir in the peanuts, remove from heat, and mix in the butter. Place the peanuts into a deep bowl, sprinkle with white sugar-salt mixture, and shake the dish to coat with sugar mixture and prevent the peanuts from sticking together. Let cool.