these are best used for pulling. buy one stack, create a macro for pulling that equips these... who cares if it hits, you got the mob. and you don't waste your pricey arrows on a pull, save them for the battle when you can put them to good use.
Well i think they are used to be cheap arrows im not a RNG yet but if im short on cash and need some arrows i would gladly buy these being only 100gil a stack
You can usually dig up either the rusty quiver or rusty bolt case with the ranger skill "Scavenger". I think its only real purpose is to give you a "cheap" arrow that you can use in order to either save real arrows till later or if you happen to run out...