Its not going to Mars that makes money, its the technology required to get there. That same tech can be used to setup asteroid mining facilities. Imagine life is found on one of the moons of Jupiter, the biological gold rush would be like nothing seen before. In addition there will be well funded people willing to travel to other worlds and moons to start new frontiers. It may take centuries but these outposts may eventually thrive opening up more economic opportunity.
Its not getting to Mars thats important, its the ability to get to Mars and what it grants humanity