Ben Kuchera is trying to find out some hard data behind the probably insane costs of Destiny. And one must agree that there are quite interesting facts that put the $500 amount more realistic. For example in comparison to Hollywood blockbusters the budget for the movie is only the cost to make the film. Not the array of other costs like promotion, marketing, PR etc.
Also Bungie spent 6 years only creating the engine. And it will be used for the whole franchise and not just the first released game (part). So the following costs of prodution will be much lower.
And we must also consider that Destiny is a HUGE trademark right now which should be on the market at least for the next decade. And in the following years will come more games, maybe movies, other platforms and connected businesses which can earn a lot of other income to the wallets of investors.
But as it is mentioned in the very end, we can only hope that this big budget means also PC version of Destiny soon. Or at least sooner than later.