Trial and Error
Location
Required Items
Rewards
What the allowance actually buys
One allowance here buys 1,711,940 EXP, the best of the 3 Lv 78 Armorer tradecraft leves that record EXP: the runner-up manages 1,306,480 EXP, 24% less.
Across that rung the return runs from 540,610 EXP to 1,711,940 EXP per allowance — 3 distinct figures spanning 217%, so the wrong pick leaves 1,171,330 EXP of the allowance unspent.
On whether to wait: the best Lv 80 Armorer tradecraft leve returns 935,000 EXP per allowance, 45% less than the best on this rung, while the Lv 76 rung behind tops out at 750,330 EXP.
At Lv 78 this data holds 27 leves paying EXP across 2 categories: the 24 Tradecraft ones average 955,432 EXP per allowance, the 3 Fieldcraft ones 2,129,178 EXP, which puts this leve 79% above its own category's average.
Dwarven Mythril Chainmail of Fending ×1 is a Lv 78 Armorer recipe, 3 steps deep through 6 intermediates, costing 29 units of raw material and 51 crystals.
Handing that in returns 59,032 EXP and 167 gil for every unit of raw material the order swallows, and the tree needs Alchemist, Armorer, Blacksmith, Leatherworker and Weaver.