The further you progress in the game, the more items and services cost. To save money, teleport back to the first town (Leaf) to sleep and purchase basic equipment (herbs, boots, etc.)
Flight
When you first get your dolphin (where you meet the third wise man), you can use your dolphin to fly at the first island you get to when you first get the man's boat. There's a little part of the island that sticks out on the left side. Take your dolphin, run into that part of the island, and jump right when you hit the part and you should fly. It might take more than one try. You will steadily lose your magic, but when you reach the next town, you can stay at the inn. After you start to fly, you can go up the waterfall and go behind the whirlpool to get your Barrier magic. You can't charge your sword while you are flying.
Get Blizzard Bracelet Early
To get the Blizzard Bracelet early, build an ice bridge on the river east of Brynmaer. After the bridge is completed, head south to the Amazon village. Once there use your paralysis power on the woman guarding Aryllis' Chamber. Step over the paralyzed woman and go inside, walking carefully past Aryllis and his guard – without touching them. (Incidental contact will cause them to speak to you, and get you thrown out of the chamber.) After creeping by, walk up the staircase behind Aryllis' throne and grab the Blizzard Bracelet that is stored in the treasure chest.
Note: You must already wield the Sword of Water and possess the Ball of Ice.
Level Charge Glitch
First, you must equip a sword that can charge to the second level, as well as the ball to go along with it. Hit Select and bring up the menu again, then swap to a sword that cannot charge to the second level. Keep the menu up and save the game, then reset - the newly-equipped sword will then be able to charge to the second level.
Pass Blockades
If someone is blocking your way (eg. the guard in Amazones) there is a way to get past him. Simply go to the side of him and walk into them twice (keep pressing A to clear the message boxes.) Next, hold the d-pad in the direction opposite of where you want to go. You eventually wind up getting past him.
Pause the Game
To pause the game press B on the second controller.
Rabbit Boots Glitch
If you use the Rabbit Boots, normally you can jump, but there's a special glitch involving the dolphin and these boots. If you were to get on and get off the dolphin while jumping with these equipped, you could hit the water, and in turn fly over the water. This glitch can be used, for example, to skip the Evil Spirit Island sequence.
Warp
To warp from one place to another while playing, do this. Press A + B on Controller One while holding A on Controller Two. A screen will appear where you can warp to several different places.
Cheaper Items ...