Hmm, It seems a bit much to me. Comparing modern military pay with the National Average. And then figuring some of the standard cost of items via the Main book.
For instance, starting pay for an officer at max is only 1,800 credits. Factoring in the fact that Military Men/Women are stationed and garrisoned, as well as fed they don't have many living expenses. I believe that is why most young military men/women have such big shiny cars/trucks and lots of new expensive toys.
I actually have some experience with this.
The reason they have a lot of toys/ nice cars is they often do not have the option of living off base and for Naval personnel spend a lot of time at sea where they do not have many expenses. Imagine what you could do if you could save your entertainment budget for half the year then spend it all at once.
I know if I took out Food/House Payment/Insurance/Upkeep/Utilities from my budget it would open a huge amount of money for me to do things with.
In the US the troops receive a housing allowance in addition to base pay. IIRC the amount is about 75% of average housing cost.
Something to remember when comparing military pay is the work load.
When at sea my average day was 10 hours working per 18 hr cycle (three shifts of 6 hrs each). In port it was 8-10 hours per normal day. In the ship yard we averaged 80 hour weeks, often 14 hours per day.
Military pay often does not reflect the responsibility either. I worked on nuclear power plants. My total pay, including meals, medical, housing, was less than half the starting pay for a civilian doing the same job. Factor in the fact I was working almost twice as many hours and isolated from the real world for months at a time my pay was JACK S#!T compared to my civilian counterpart.
You should also consider the quality of living for enlisted personel.
I spent may years living in barracks rooms 15' x 20' shared with one or two other people. On board ship our personal space was our bunk (never tall enough to sit up in) and a 2' x 2' x 3' locker.
I did some number crunching on the present US pay charts and came up with some trends.
Base pay increases 15% per pay grade
Base pay increases 5% every two years
Base pay at a given pay grade stops increasing at a point where you should have exceeded that rank. For those not familiar with the US pay grades there are 9 enlisted and 10 officer ranks. For the middle pay grades the pay stops increasing at (grade x 2) + 2 years, officers at (grade x 4) + 2 years. The lower 3 enlisted ranks should be past in less than two years so they do not get time in service pay increases. Same for the two lowest officer ranks at 3-6 years. At E-7 and O-6 there is no max pay other than 26+ years service, the number of positions at the higher pay grades is much smaller so there is no penalty for not progressing in rank.
For example a Commander (O5) with 12 years service would make
(Base x 1.15^5) x 1.05^(12years/2)
Using $1100 as a base pay, before special duty/ deep space pay and housing, it works out to $2900 per month.
Based on US Navy pay charts I would assign the following special pay expressed as a percentage of base pay.
Space pay (ship or station) 12 % enlisted, 8 % officers
Deep space pay (expected deployments of > 9 months per year) 10%
Hazardous duty 10% enlisted 5% officer
Imminent danger/ hostile fire pay 10% enlisted, 5% officer
The above character assigned as a pilot on B5 (space, pilot, hostile fire) would make about $3600 per month plus housing and meals.