Re: Why only 2 oz ?
It would make for a more complicated mission profile, which in turn would push up the costs enormously, as well as making the mass budget for the mission a whole lot more complicated.
For example, it took NASA months to plan out this single sample collection. Adding additional samples would extend the planning process much longer, and would mean that the spacecraft would have to reposition itself and change its orbital profile a lot more. This would require a lot more fuel, and pushes the mission risk up significantly.
Another example, in order to take multiple samples, the spacecraft would have to be fitted with multiple collector heads to ensure that sample cross-contamination does not occur. In addition the return capsule would have to be made larger to accommodate all of the samples which in turn would mean a larger landing system (i.e. bigger parachutes).
Biting the hand that feeds IT
