500k is not that outlandish for a system like this. Cameron Purdy, who developed Tangosol (now Oracle) Coherence said that he regularly turned down $500k job offers. Bear in mind that their idea of "top notch" is not what gets bandied around here as "rock star". They're not programming Rails. They're talking people who have had their shit together since day one, have always been top of their class even after they got into the best universities, and have applied themselves their whole lives to the theory and practice of building big systems. I've built some biggish systems but I still spent a large amount of my university years and youth generally studying beer, skirts and house music. It makes a difference, I'm a long long way from what they're talking about.

Here's how I would think about it if I were building this. The total hardware costs are 168M, and the total personnel costs are 4M. Say I pay $500K instead of $200k and in doing so I get Jeffrey Dean instead of someone like me (I suspect I might have to pay more than $500k for Jeffrey Dean but bear with me). My costs have doubled but the efficiency of the system might be 5x or 10x better because I'm just quite good at my job and he's a total legend. That efficiency scales the total hardware cost, which dwarfs the personnel cost. I'd say $500k starts to look pretty cheap at that scale.

It's the cost of renting a developer with security clearance from BAH. Snowden would likely be in the same salary band as a "supporting developer." He was taking home $122K, thus his actual cost to the government was likely $250-$300K.

This is what's referred to as "blood money".

I wouldn't sell out my fellow man for anything less.

Considering the scale, and importance of the system that seems low.