Here is the actual text for the requirements to be a GS-13 employee (and they are strict on these)
"GS-13 Federal Employee Base Salary GS-13 government employees will receive a base salary of between $76,687.00 and $99,691.00, depending on their General Schedule Step. The educational and experience requirements for most GS-13 government jobs are: Master's or Ph. D."
For most companies in that area, you can paid that salary or more right out of a Bachelor's. I've worked a government job before amd always felt undervalued, even compared to contractors who were ok n the same team as me (they were making nearly 40% more than I made with similar experience).
And I'm almost positive if you take this position, you'll be working on propping up old, irrelevant tech from who knows how many years ago.