Make sure you have 2 "Kelbi Horns" in your item pouch. Talk to the "Guild Sweetheart" at Moga Village. Select Low Lv one star "Prescription Pick-up" gathering quest. Deliver the 2 "Kelbi Horns" right away. Quest complete. Take the 2 "Kelbi Horns" from the reward box and sell/collect the rest of the items. You'll received 800z for completing this quest. Repeat this method to obtain easy Zenny.