I've noticed that many Hawkers have trouble with money. It's the arrows. They all buy expensive arrows like those white fire things, or Claw Arrows. The problem is, better arrows don't give you much of an advantage.
Now, think. How many arrows does it take for you to kill a monster with a yellow name? 5? 6? 8? What about an orange-named monster? 15? How about a green, cyan, or white-named monster? 1? 2? Much less to kill the monsters weaker than you, in any case.
Assuming you get the same money from each monster, it is much more cost effective to use 1 or 2 arrows on a monster than to use an average of 10 arrows, correct? Of course, in R.O.S.E. you don't get the same money for each monster.
In fact, if you buy 999 Wood Arrows when you are level 15, and use all of them to kill Jelly Beans, Jelly Nuts, Red Jelly Beans, Royal Jellies, Little Jelly Beans, Little Chorpys, and Chorpys in the Adventure Plain, you get MANY TIMES as much money as if you were killing monsters in the desert, or in Zant using those same 999 arrows. You may not seem to get as many Etc. items from the Adventure plain monsters, due to the fact that your level is so much higher, but trust me, in the end, you get more Etc. items per arrows than otherwise. Even better, the Red Jelly Beans have been know to drop Iron Thread relatively often. Either put those to good use, or sell them to other players for upwards of 1k.
However, there is one flaw to this strategy: the lower-level characters trying to level up against these monsters you're commiting genocide on. Some might say you're Kill Stealing. Just ask your consience this: is it a Kill Steal to kill a monster before that young Visitor planning to become a Soldier even reaches it? Is it a Kill Steal to save a soon-to-be Muse from a hoard of Jelly Beans that often attack when a lower-level character kills one or two Jelly Nuts? And, is it really Kill Stealing when there's 20 more creatures of the same type on the screen? If you can answer NO to these questions, then by all means, use this method for a Hawker (or any character with a weapon that uses ammo) to gain money. If you answered YES to any of my questions, reconsider.