Wonder Boy in Monster Land

If the rapid trick has been put to good use, then you will have enough money to purchase all of the legendary equipment but the sword before your encounter with Sphinx. Keep in mind though that legendary equipment will not appear for sale in shops unless you have already bought equipment two tiers down. Here is what you will need to obtain:

Boots:
Cloth - 50 gold
Leather - 80 gold
Ceramic - 180 gold
Legend - 380 gold

Shields:
Light - 40 gold
Knight - 120 gold
Hard - 250 gold
Legend - 360 gold

Armour:
Light - 60 gold
Knight - 150 gold
Heavy - 100 gold
Hard - 360 gold
Legend - 540 gold

Great Sword - After fighting three sandmen in the caves of Round 5, you will see an "OH!" message appear on screen. Hit on your controller and prepare to fight a secret boss, the Giant Kong. To defeat him, just keep going towards him and attack and as soon as he jumps over you, turn around and repeat. After you defeat him, you will receive the Great Sword.

Sword of Legends - In the cave of Round 8 and on a platform on your way down, hitting on your controller will make another door open. This will unlock another secret battle with a Demon. This boss has a circle of fireballs rotating around him, which follows a pattern of increasing and then decreasing in size. When you see a safe opening, then is your chance to strike. Defeat the Demon to receive the Sword of Legends as well as the trophy.