After living and working in the Washington DC area for 40 years, I can say with 100% certainty that it is not a place where you will find reasonably priced housing or other cost of living items.
Unless the Postal Inspector job pays $80-100K/year you are looking at living in a distant suburb and spending many hours driving commute.
I live in the western edge of Fairfax County VA and do a lot of business with our tiny local PO and have gotten to know the folks there (it’s a 1.5 person office) and they all live in locations that require at least an hour commute from their homes to the PO. Our new Postmaster must spend closer to 3 hours on the road total commute time considering where she lives.
Different story if your job does not require working in the immediate DC area (The District and the VA and MD counties immediately adjacent to the District). There are some very pleasant and moderately priced parts of Virginia once you get outside the immediate DC area.
I would under no circumstances consider living in MD because its politics are driven by Baltimore and Montgomery County (DC area) and are hard left, even though it showed some signs of sense in putting a couple of more conservative R people into state office.
Yeah it doesn’t pay that much. 40-60K, and adjustable on certain locations and I’d have to find that list again.
I know it includes places like Alaska and Hawaii as 25% increases, but there’s a few others.
Double ditto to Jack’s recommendation of AVOIDING Wash DC.