I was puzzeled over that number too, as putting up a site like that, even if you are buying the servers from scratch and hire a first rate web dev, shouldn't cost more than 10-20k$. I went through to the linked artice, and appeareantly, most of it went for consultants.
I mean there are consultants out there that are worth their money, and I bet the site is kai-zen optimized very nicely, even though I can't tell, but 327 million $ is quite a hump for that website. The main problem seems to be that government contracting is not a regular market, else joe's jquerry shack would have ourrun and outpaced accenture in both cost and quality.