Red Dragon is currently in the news again. Except for its enormous amount of ambition and its relatively large risk of failure (e.g. Falcon Heavy RUD, a SuperDraco failure on Mars, mixing imperial and metrical units etc.), it seems to be relatively straightforward:
- Stuff Dragon II with enough fuel for re-entry and landing
- Put onto Falcon Heavy
- Aim and shoot
The "aim" part is even supported by NASA free of cost. However, the whole Mission still will cost around 320Million \$. A single Dragon II launch is proposed for 140Million\$ (still quite expensive) - including SpaceX margin. That still leaves 180Million$ for the "Mars part".
When SpaceX is going to launch that mission in 2018 and support it until 2020 (next launch), that makes 40Million $ annual budget, or roughly 200 exceptionally qualified engineers. Since SpaceX probably does not pay that many people that well for a single mission:
Where does all that money go?