OK, well this may or may not apply to your server, but the tenshodo salesman in bastok that sells these for about 597g or so is my best friend ^^. I buy them from him for that much and sell them in Bastok's own AH for 2.5-3k. This is mainly because Asura's Bastokan AH is always in turmoil. However, if it does apply to your server it's an easy way to turn 600g into more. Just another part where tenshodo membership pays off.
OK, well this may or may not apply to your server, but the tenshodo salesman in bastok that sells these for about 597g or so is my best friend ^^. I buy them from him for that much and sell them in Bastok's own AH for 2.5-3k. This is mainly because Asura's Bastokan AH is always in turmoil. However, if it does apply to your server it's an easy way to turn 600g into more. Just another part where tenshodo membership pays off.
A better way to turn profit is add a 500 gil Lightning crystal to that 597 gil Kunai and desynth it into a steel ingot. Wham-o! you have a 5000 gil or more profit now.
This weapon is slightly better delay than the equivalent dagger, and thus is probably a decent deal if you have the spare cash. Plus, it's a lot more badass than an onion sword.
Because the Ninja Flag quest ends in Bastok, you can sometimes pull a profit trading Kunai if you have a Tenshodo membership. I was able to buy Kunai for around 600g, and because nobody else was trading them on my server at the time, I was able to sell about 10 of them for 1200-2000g before the bottom fell out. I found I sold about 3 every 2 days. Try not to sell more than 2 at a time, or else it'll seem like they aren't scarce and players will try to lowball you.