With some of the income and infrastructure from this project, why not use it as a way station for Mars expeditions? Build a self sufficient habitat and inject it into the favorable orbit between L5 and Mars. Then every two years a group of colonists could ride it with very little fuel expenditure to Mars. They would need to park their descent vehicle nearby. Food, water, and radiation protection could be provided in the habitat, with artificial gravity and greenhouse food production managed by a team of robots during the long sector of the orbit.