Cost.. it's a kevlar helmet.. my estimate is $250 minimum. This
is based on getting an American helmet from a surplus store.
AS for buying them, as far as i know it is illegal since it is a
ballistic helmet. Singapore Police does not allow unauthorised
possession of ballistic armour army market aunty/uncle is not
authorised.
My best bet for you is you go reservist again and request from QM.
Pay 1206. or he good enough, he has some sitting around. Or you go
ask the ROD'ed personnel.