With the city soon to be submerged beneath the waves, power outages are likely to follow, except for those lucky (or prescient) few with backup generators. Which means a sturdy flashlight powered by dependable D batteries may be the only light to be had in the coming darkness. How much would you fork over for this hurricane must-have? With everywhere from Whole Foods to your local Williamsburg bodega a scene of mad stockpiling, just how much of a disaster premium people are wiling to pay?