When you pay for a meal in a restaurant you are not just paying for the individual ingredients that make up the dishes but the combination of the ingredients + the expertise of the chef + the place where you enjoy the meal.
A Michelin star chef can turn 5 euros of ingredients into a meal that is sold for 50 euros.
Therefore cost of projects must include the cost of ingredients (software, hardware, materials etc) and the cost of the project team members’ skills and expertise to turn these ingredients into a world class dish.
Successful International Project Management 