On MinecraftWar Money is a crucial factor in winning wars, Rich Factions will normally win over the poor factions this is because you can buy items on the fly during the fighting.
If you need some more arrows you would just buy it from the shop, now if you had no money you of course couldn't do this.
Basic money commands
/money - To check your balance
/money help - Display help for iConomy
/money rank (player) - View rank on top charts
/money top (amount) - Richest player listing
/money pay (player) (amount) - Sends money to specified player
/shop help (page) - Shows help page for Shop
/shop list (page) - List items on sale or for purchase
/shop check (item id) - Shows information about item
/shop sell (item-id)(:type(if any)) (amount) - Sells specified items according to id and amount
/shop buy (item-id)(:type(if any)) (amount) - Buys specified items according to id and amount
/shop gift (receiver) (item-id)(:type(if any)) (amount) - Gifts to specified player according to id and amount
Shop ID List (Only the items that are available on this server)