A set of OD (pants, and tunic) is like $30 and they are plenty available in most Surplus stores.
That should only really be the basic requirements and you should consider skirmishes rather than full out milsims.
Most teams are really accepting of newbies and want to expand instead of running with the same 10 guys forever they will probably want the team to grow so there's more variety and more people to play against. Note that is only for general clubs and teams. Specific teams may have strict requirements (eg. WWII reenactors, PMC, milsim oriented teams).
ಠ_ಠLess QQ more Pew Pew
READY TO >> RACE