n a special sales order decision, incremental fixed costs which would be incurred because of an additional purchase of equipment would be considered to be: relevant to the decision. irrelevant to the decision. opportunity costs. sunk costs.

A product that has few substitutes tend to be inelastic. Inelastic because they are unique products that you can only find few substitute on it. One of the most famous example is gasoline, in any case you cannot find any substitute to gasoline to make your car run even without it.