If they don't reload, then a brick of 22 long rifle rounds. A brick (350-500 rds) will run about $21 to $30. The 22lr will be worth its weight in gold, if bad things happen. With 22lr, you can shoot it or use it for trade.
If either of them smoke get them a Top-o-matic cig machine, a pack of small pipe tobacco and a box (200) of blanks. They can roll their own smokes then....will set you back around $60 and they will get a carton of cigs.....from there on out they can buy the stuff to roll their own at roughly $1.25 a pack.
I roll my own, takes 10 minutes to roll a pack.