According to Wikipedia the annual budget per employee at CSE calculates to be approximately USD$220,000/employee, which would be far less than the cost of hiring a typical NSA contractor[1]. This of course assumes that CSE doesn't have any other expenses (buying hardware, paying electricity bills)!

If CSE employees don't find the salary competitive now, you can almost be certain that 9/10 people working there in a few years time will be on much higher contractor rates.

[1] https://www.marketwatch.com/story/the-average-defense-depart... (these figures are extremely conservative as they're from 2015, not specific to high demand ICT jobs, and also without the scarcity in the job market that a TS/SCI clearance creates)