I retired from CBP in January. I was a gs-13 step 9
My base was 105k then you get LEAP which adds 25% so I was making roughly 130-135k. Federal LEO retirement is figured different than normal civil service. You get 1.7% per year for your first twenty and 1% a year after that of your high three years plus a social security supplement. You can retire at 20 years if your over 50 and anytime if you have 25 years in. Generally new hires start as a gs11 for a year then a gs12 for a year then a 13. GS13 is top unless you go into management or fly the P3.
The GS scales are published on the OPM Website. Look for the special salary rate for LEO then add 25% to get an idea of pay. Some of this may have changed but that's the way it was.
I did way better than my friends who went to airlines for a while, now they are all at majors and will far surpass my career earnings.