That's money wasted if it can't help a saw owner work in a tight space. I doubt that the base with those small castors can work even in an ample shop for a saw that weighs between 500 to 650 pounds (depending on the models/accessories installed).
The SawStop is a top-end cabinet saw and saving money on the mobile base or dust collection (it has the best d.c. among all cabinet saws tested in the latest issue of Wood magazine) in my opinion would degrade its full capability. There is a reason why SawStop offers one of those two items free during its promotion sale (which is still on), because it knows its competitors can't match those features.
Simon