Better Trim Recipes is a simple plugin that replaces vanilla armor trim duplication recipes with more balanced versions. This makes them cheaper to duplicate so you aren't using seven precious diamonds to customize your armor.
All materials used are somehow related to the trim. For a few examples, the ward and silence armor trims use echo shards and Deepslate, the eye armor trim uses an eye of ender and Endstone, and the bolt trim uses a diamond and copper blocks.