I think the Mars goal helps them a lot with obsoleting their best product. It was obsolete from the start - they knew this one never goes to Mars, it's just a test bed for technologies and a money maker that helps them on the way. While other companies developed their best rocket and then tried to keep it running as long as possible to recoup the investment and make as much money from it as possible, Musk was talking about the next rocket before first Falcon 9 landing.