What You Need

One allowance here buys 18,910 EXP, which places it 2nd of the 6 Lv 15 Carpenter tradecraft leves that record EXP — a figure 1 other leve on the rung matches exactly. The best of them, Nothing to Hide, returns 24,790 EXP for the same allowance, 31% more.

Across that rung the return runs from 7,170 EXP to 24,790 EXP per allowance — 5 distinct figures spanning 246%, so the wrong pick leaves 17,620 EXP of the allowance unspent.

On whether to wait: the best Lv 20 Carpenter tradecraft leve returns 28,010 EXP per allowance, 13% more than the best on this rung, while the Lv 10 rung behind tops out at 13,090 EXP.

At Lv 15 this data holds 52 leves paying EXP across 2 categories: the 48 Tradecraft ones average 16,554 EXP per allowance, the 4 Fieldcraft ones 78,432 EXP, which puts this leve 14% above its own category's average.

Gil ranks it differently: 170 gil per allowance is 6th of 6 on the same rung against 2nd on EXP, with the best there paying 350 gil.

Square Ash Shield ×1 is a Lv 15 Carpenter recipe, 3 steps deep through 3 intermediates, costing 9 units of raw material and 7 crystals.

Handing that in returns 2,101 EXP and 19 gil for every unit of raw material the order swallows, and the tree needs Blacksmith and Carpenter.