I've never built a time keeping system, but this is how I put that number in perspective. For $63 million I can hire everyone who's ever been a Django core developer (people I've worked with, and who are excellent) for 5 years, at 500k a year... and there'd be money left over.
Building a time-keeping system for large city like NYC is many,many times more work than building web-framework like Django. It's not a technically complicated problem, but it has a different kind of complexity. That complexity comes complex business requirements, which have to be analyzed and implemented piece-by-piece.
