$550 is assuming u get your 3SG. and even if u really got it,
it'll be many months later from the day u enlist for u to get that
anoumt, cos the course will be very long and depending on how
efficient your S1 is at doing their job.
if u don't get selected for tech and ended up as a
clerk/storeman/driver, u will only be geting $350 to $400+
(depending on rank, PTE, LCP, CPL).
if stay out, at least $50 goes to transportation, $100 for personal
use. assuming u are not a big spender and don't smoke, saving a few
hundreds every month is still possible.