Say It with Spears

One allowance here buys 9,430 EXP, which places it 3rd of the 6 Lv 10 Carpenter tradecraft leves that record EXP. The best of them, Life's a Stitch, returns 13,090 EXP for the same allowance, 39% more.

Across that rung the return runs from 3,780 EXP to 13,090 EXP per allowance — 6 distinct figures spanning 246%, so the wrong pick leaves 9,310 EXP of the allowance unspent.

On whether to wait: the best Lv 15 Carpenter tradecraft leve returns 24,790 EXP per allowance, 89% more than the best on this rung, while the Lv 5 rung behind tops out at 6,840 EXP.

At Lv 10 this data holds 52 leves paying EXP across 2 categories: the 48 Tradecraft ones average 8,265 EXP per allowance, the 4 Fieldcraft ones 43,676 EXP, which puts this leve 14% above its own category's average.

Feathered Harpoon ×1 is a Lv 13 Carpenter recipe, 2 steps deep through 2 intermediates, costing 8 units of raw material and 4 crystals.

Handing that in returns 1,179 EXP and 22 gil for every unit of raw material the order swallows, and the tree needs Alchemist and Carpenter.