If the missing chart is the chart in my attachment, Ezra's opportunity cost if he decides not to expand is most likely the 4TH BENEFIT which is MAKE AND SELL MORE FOOD ITEMS.
I chose that option among the benefits because it is the benefit that clearly translates into dollar values by being potential sales revenue. If Ezra gives up the idea of expanding, he will lose his potential sales or the opportunity to sell and gain more profit.