Professor E. Gadd's lab features a shop where you can purchase useful items using the money you collect. Key items include the 'Gold Bone,' which revives Luigi if he runs out of health, and 'Boo-Finder,' which helps locate Boos. You can also buy 'Gem-Finder' to highlight hidden gems. While not character builds, these items provide significant advantages and can make your journey easier, especially for completionists.
