Your implementation isn't terrible, but you should spend more time thinking over your gameplay idea before you start developing. For example, you could include custom orders and time limits to introduce a little challenge into how you prioritize acquiring and forging the various gems. Or there could be minigames to represent the journey of the adventurers or process of the blacksmith. Perhaps different adventurers could be hired, at different prices, but whom would produce results in a shorter time or with more reliability. Currently you have a framework, but there is neither skill nor strategy in the gameplay.