Ultimate Wooden Chest

Worth: 345  Maximum Stack Size: 100 Recipe Cost: 1,910  Recipe worth: 1  Recipe Sold by: Martin Borsten This item is created by Carpentry (95). This item comes from:  Package 4

Ultimate Wooden Chest Prepared Materials Worth: 345 Gold Material for making rarity 3 carpentry products.  Recipe - Ultimate Wooden Chest Requires Carpentry level 95 Raw Materials:  Fire Mountain Tree Lumber ×4  Rainbow Stone Ingot ×2  Link Rune ×1  Bleak Fir Lumber ×1 Worth: 1 Gold Product(s):  Ultimate Wooden Chest ×1

Very few Crafted items have no upgrade path, but this appears to be one of them.