Technically Still Magic
Location
Required Items
Rewards
What the allowance actually buys
One allowance here buys 2,297,800 EXP, the best of the 2 Lv 88 Alchemist tradecraft leves that record EXP: the runner-up manages 1,494,330 EXP, 35% less.
On whether to wait: the best Lv 90 Alchemist tradecraft leve returns 2,695,430 EXP per allowance, 17% more than the best on this rung, while the Lv 86 rung behind tops out at 2,028,020 EXP.
At Lv 88 this data holds 18 leves paying EXP across 2 categories: the 16 Tradecraft ones average 1,852,163 EXP per allowance, the 2 Fieldcraft ones 3,242,290 EXP, which puts this leve 24% above its own category's average.
Gil ranks it differently: 5,020 gil per allowance is 2nd of 2 on the same rung against 1st on EXP, with the best there paying 5,040 gil.
Ophiotauroskin Magitek Codex ×1 is a Lv 88 Alchemist recipe, 3 steps deep through 5 intermediates, costing 34 units of raw material and 72 crystals.
Handing that in returns 67,582 EXP and 148 gil for every unit of raw material the order swallows, and the tree needs Alchemist, Goldsmith, Leatherworker and Weaver.