If they retire the Concorde I'll be at the scrap yard and will purchase EVERY SINGLE ONE! The major cost of the Concorde was a fixed cost (R&D, Concept, Construction, etc.) The Concordes are still making money for BA & AF. The variable costs are high (Fuel, maintenance etc.) but they are worth the cost. If they are removed from service one could purchase them and still make them profitable. The only way they would cease to be profitable is if some one developes a subsitute product, IE the spaceplane, but as we all know that is a pipe dream and if the concept happens it will be in the mid to late 21st century. Just the view from third year business student.