Heads Will Roll

One allowance here buys 408,920 EXP, which places it 3rd of the 3 Lv 68 Armorer tradecraft leves that record EXP. The best of them, Spoony Is the Bard, returns 681,530 EXP for the same allowance, 67% more.

Across that rung the return runs from 408,920 EXP to 681,530 EXP per allowance — 3 distinct figures spanning 67%, so the wrong pick leaves 272,610 EXP of the allowance unspent.

On whether to wait: the best Lv 70 Armorer tradecraft leve returns 565,870 EXP per allowance, 17% less than the best on this rung, while the Lv 66 rung behind tops out at 969,450 EXP.

At Lv 68 this data holds 27 leves paying EXP across 2 categories: the 24 Tradecraft ones average 550,185 EXP per allowance, the 3 Fieldcraft ones 1,189,544 EXP, which puts this leve 26% below its own category's average.

Molybdenum Headgear of Maiming ×1 is a Lv 68 Armorer recipe, 3 steps deep through 5 intermediates, costing 30 units of raw material and 36 crystals.

Handing that in returns 13,631 EXP and 42 gil for every unit of raw material the order swallows, and the tree needs Alchemist, Armorer, Blacksmith, Leatherworker and Weaver.

The record carries a repeats value of 2. This site reads that as 2 further turn-ins on the same leve — an assumption, because the source data defines no meaning for the field — which would put the ceiling at 1,226,760 EXP and 3,786 gil for the 1 allowance it costs, or 1,226,760 EXP per allowance.