I don't know that sending a rover to look for "sedimentary rocks" and "lava flows" would ever be worth it- but wind sedimentary and "pyroclastic" mud flows are a different matter. You could get a lot more information about these from a rover than from a stationary lander.

But ss far as science goals go, I think ultimately you have to come back to Goldin's goal in his manned Mars plan - which was a series of probes to clear back contamination as a possible road block to manned Mars flight.

Minimally, if NASA is going to land a stationary lander right now, they need to set up some kind of site committee immediately if they are going to get our money's worth for this launch, and the entry programs have to be re-worked to ensure a landing absolutely as near as possible to the choosen site. As NASA already employs people capable of doing these jobs, whether they get these jobs done or not is a question of "management leadership" within space sciences.

Thinking a litttle further, maybe you're right. With no govenrment Mars rover, the market will be cleared for private sector Mars rovers, and Musk's launcher appears to be coming along well. Also, I see IKI has had a Mars rover approved, and the possibility exists of selling its imagery via the internet instead of giving it away for free, and in this there remains a possible role for outside firms. Would you really trust any Russian computer system with your credit card information?