FFO Name: Bottled Faerie
"Bottle containing a faerie."
Price: 50000 / 40000
You can buy the Bottle from the Caravan for a whopping 50,000G. It contains the fairy, which will return to her spring in Gaia when you release her. As long as you don't open it you can revisit the Caravan and buy as many bottles as you want. It won't do you any good though, you'll still only have one. The remake will only allow you to buy one though. After that you can purchase Potions, Antidotes, and Gold Needles from the Caravan.
The Bottle is called the Fairy Bottle in the Japanese version. Kinda takes away from the mystery doesn't it?