Battle Rapier

A Battle Rapier is a Light Blade-class weapon available in throughout the Golden Sun series. In Golden Sun, the Battle Rapier is bought in the towns Xian, Altin, and Kalay. In Golden Sun: The Lost Age it is bought in the towns Naribwe, Kibombo, and Yallam. In Golden Sun: Dark Dawn, it can be bought in the towns Ayuthay, and Passaj. Being a Light Blade-class weapon, a Battle Rapier can be equipped on Isaac, Garet, and Ivan in the first game, together with Felix, Jenna, and Piers in the second. In the third game, it can be equipped by Matthew, Tyrell, Karis, Amiti, Eoleo, and Himi. It increases the wielder's base Attack rating by 58 points. Its buy value is 2900 coins and its sell value is 2175 coins.

Analysis
In Golden Sun when it can be first bought in Xian, it is a worthy purchase for an Adept holding a Broad Axe, and if Ivan is holding the Elven Rapier while Mia is still holding the Blessed Ankh, it would be feasible to buy a Battle Rapier for Ivan. Buying Battle Rapiers should not take priority over buying the new and stronger defensive equipment at Xian, though, and unless you have money to burn buying multiple Battle Rapiers might be overkill because in the next town of Altin is where you can buy Claymores and the Psynergy Rod artifact from the weapon vendor you can de-submerge as you progress through the Altin Peak dungeon.

In Golden Sun: The Lost Age, much of the game's focus is on  completing puzzles in the dungeon-style locations that  provide as  rewards weapon artifacts far superior to commonly bought  weapons and  even weapon artifacts that can normally be bought in  vendors, so you  will most likely not want to buy and equip this weapon  because you will  have very easily found superior weapon artifacts such  as Storm  Brand, Hypnos' Sword, and Blow Mace before you  even get to the  towns that sell Battle Rapiers. The Battle Rapier may have a higher  attack rating than the Hypnos' Sword in particular, but  it doesn't have  an Unleash effect, which makes it actually less useful.

In Dark Dawn, the Battle Rapier, like all common weapons, is given a slight revision, in that it now has two Unleashes: Critical Strike, a non-elemental attack that multiplies damage by 1.5, and Berserk Rush, a non-elemental attack that multiplies damage by 1.6.

When Amiti joins the party in Ayuthay, he will have a Battle Rapier equipped and will have mastered both Unleashes. At this point, a stronger weapon can not be acquired at least until the Weapons Shop in Passaj opens, at which point he can equip a Composite Bow. However, thanks to the good damage multipliers of the Rapier's two Unleashes, the Battle Rapier will still serve him well until then.