Gold is an optional resource, as you can play most of the game without using any Gold whatsoever. Premium Buildings, Premium Houses, and Premium Decor cost Gold, but are not essential to the game. A few Quests do ask you to spend Gold on Premium Decor. Additional Helpers also cost Gold. And any Phase of a Quest can be completed just by paying a bribe in Gold. Curiously, when you receive a Quest that asks you to spend Gold on a Premium item, it typically costs less Gold just to complete the Quest immediately, without paying Gold for the item. You don't receive the item, but you complete the Quest and save some Gold.
Helpers and Premium items can go on Sale, where it costs less Gold to buy them. A typical discount is 40% to 60%. So save all your Gold purchases for the Sale!
Strategically, if you spend your Gold on:
- Premium Buildings, they will give you Coins, helping you to buy the non-premium items
- Premium Houses, they will give you Cheer, helping you to speed up the game
- Premium Decor, it will increase Happiness, allowing you to build more non-premium Houses
- Helpers, they will let you finish more tasks simultaneously
In the early game, Coins will be the most important. Build the Boomerang Hall with your first 13 Gold, as it will also give you a steady supply of Planks. The Premium Buildings that give you Special Items as well are best use of Gold overall.