Oops, TIL that MyPay only keeps your last 12 paychecks, so I can't look at the first payment, but the second one (which for some reason shows up as UEA initial, even though I suspect that means Uniform Enlisted Allowance) was for $400.
I can look at the first payment in USAA and work backward though.
Okay, so my first paycheck was for about 3 grand, and the next bimonthly was for 933, so it looks like the initial allowance payment was around 2 grand. If you don't get the Brooks Brothers SDB's, you should be pretty close to being in the black, but if you wear the blues a lot as a suppo, I'd consider splurging, they're really nice. But that's a decision you'll have to make a long way down the road, something like week 6.