It's a surprise even if you restrict your point of view to the narrow economic interests of his employer, UCLA, who benefits from Tao's discoveries. Shelling out another 50k or so for an assistant, even if it boosts his productivity by only 10%, is a no-brainer.
If you expand your point of view to the interests of all mathematicians, or society at large, the waste here is even more extravagant.
If you expand your point of view to the interests of all mathematicians, or society at large, the waste here is even more extravagant.