The Whitebrim leve is a much better option Final Fantasy 14 Gil as Peiste Skin and Black Alumen both tend to be quite cheap. It is cheaper and easier to do than the Boarskin Harness leve.
Level 45 Repeatable Leves
Gridania: 3x Peisteskin Cesti (5x Earth Shard, 1x Steel Ingot, 1x Peiste Leather, 1x Raptor Sinew)
St. Coinach’s Find (Mor Dhona): 5x Raptor Leather (5x Earth Shard, 1x Raptor Skin, 1x Black Alumen)
The Raptor Leather leve at St. Coinach’s Find is the best choice here. Like Boar Leather, you can sometimes find very cheap Raptor Leather on the Market Boards. Leatherworkers are eager to synthesize this since it builds up spiritbond on top-level gear.
Recommended Leatherworker Grinding Options By Level
Levels 1-5: Leather – 1x Earth Shard, 1x Animal Skin (buy from guild supplier)
Levels 5-13: Hard Leather – 1x Earth Shard, 1x Animal Hide (buy from guild supplier)
Levels 13-17: Hard Leather Choker – 1x Earth Shard, 1x Wind Shard, 1x Hard Leather, 1x Beast Sinew (use Hard Leather you made the previous levels, buy Animal Hide off guild supplier)
Levels 17-24: Aldgoat Leather – 1x Earth Shard, 1x Aldgoat Skin, 1x Alumen (buy both off Market Boards. Consider turning in for repeatable leve at Gridania).
Levels 24-30: Goatskin Choker – 2x Earth Shard, 2x Wind Shard, 1x Aldgoat Leather, 1x Diremite Sinew (buy Diremite Sinew off Market Boards. Consider turning in for repeatable leve at Costa del Sol)
Levels 30-35: Boar Leather – 4x Earth Shard, 1x Boar Hide, 1x Alumen (consider turning in for repeatable leve in Gridania – this starts to get expensive).
Levels 35-36: Boarskin Choker – 4x Earth Shard, 3x Wind Shard, 1x Boar Leather, 1x Hippogryph Sinew (consider turning these in for the repeatable leve at Observatorium in Coerthas)
Levels 36-40: Peiste Leather – 4x Earth Shard, 1x Peiste Skin, 1x Black Alumen (buy Peiste Skin and Black Alumen on the Market Boards)