The guy who sells you weapons throughout the world has a shop set up in Lestallum. Talk to him and he will give you some quests to go on.
Ace of Carapace – Level 15 Quest
The merchant will ask you to find him some carapace’s, so travel West of the Kelbass Grasslands. Fight a group of Bulettes to acquire one, then return to the shop. He will give you 1500 EXP and lower shop prices.
Tails Spin – Level 20 Quest
The arms merchant needs some supple tails. Follow the map and fight a small group of Spiracorns. Retrieve the tails and go back to Lestallum. You’ll get 2000 EXP for your hard work.
Sting Your Praises – Level 25 Quest
The next quest from the arms merchant requires you to travel over near Ravatogh. Head there and fight a few level 25 Saphyrtails. Take the loot you get back to the merchant for 4000 EXP and lower store prices.