Hallowed Chestnut Lumber

Taken all the way down to base materials, one Hallowed Chestnut Lumber is 2 crafting steps deep and needs 2 intermediates — Hallowed Water ×2 and Dark Chestnut Lumber ×1 — which resolve to 3 distinct raw materials totalling 9 units, plus 14 crystals.

That bill outweighs 5,492 of the 13,602 recipes tracked here and 549 of the 1,552 Carpenter ones, and 4,464 recipes nest deeper.

Only 5 of those crystals go into the final step; the other 9 are burned by the intermediates, so the real crystal cost is 9 Wind Crystal and 5 Water Crystal.

The chain crosses two disciplines — Carpenter to Lv 56 and Alchemist to Lv 56 — so no single class can finish it unaided.

All 3 raw materials are gathered, and one of them is time-gated: Abalathian Mistletoe (6:00, 18:00). The widest gap between consecutive opening times is 12 Eorzean hours, about 35 real-world minutes.

Hallowed Chestnut Lumber is itself consumed by 32 further recipes, spanning six of the eight crafting classes.