A Drag of a Doublet

One allowance here buys 24,790 EXP, the best on the Lv 15 Weaver tradecraft rung — matched exactly by 2 other leves of the 6 there, with the rest trailing at 21,850 EXP or less.

Across that rung the return runs from 20,790 EXP to 24,790 EXP per allowance — 3 distinct figures spanning 19%, so the wrong pick leaves 4,000 EXP of the allowance unspent.

On whether to wait: the best Lv 20 Weaver 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 50% above its own category's average.

Initiate's Doublet Vest ×1 is a Lv 20 Weaver recipe, 3 steps deep through 4 intermediates, costing 8 units of raw material and 7 crystals.

Handing that in returns 3,099 EXP and 37 gil for every unit of raw material the order swallows, and the tree needs Goldsmith, Leatherworker and Weaver.