When you go to Rebena Te Ra, buy out everything in the Mog Shop. To get to the Mog Shop, go up the steps leading to the Crystal Temple, but do not go in. Instead, jump in the upper-right direction before you pass the guard. You will see a Moogle at a shop stand. This is the Mog Shop. Buy everything, and when everything is sold out, do a quest. After completing the quest, check the Mog Shop again. There should be more items in the shop. If you run out of quests to do, complete an easy dungeon, such as the Valley of Heroes. Keep doing this as many times as desired. The Mog Shop will never run out of items to restock.