I'm into Leather

One allowance here buys 9,990 EXP, which places it 2nd of the 6 Lv 10 Blacksmith tradecraft leves that record EXP — a figure 3 other leves on the rung match exactly. The best of them, Twice as Slice, returns 13,090 EXP for the same allowance, 31% more.

Across that rung the return runs from 8,430 EXP to 13,090 EXP per allowance — 3 distinct figures spanning 55%, so the wrong pick leaves 4,660 EXP of the allowance unspent.

On whether to wait: the best Lv 15 Blacksmith tradecraft leve returns 18,910 EXP per allowance, 44% more than the best on this rung, while the Lv 5 rung behind tops out at 5,220 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 21% above its own category's average.

Gil ranks it differently: 529 gil per allowance is 1st of 6 on the same rung against 2nd on EXP, with the best there paying 529 gil.

Brass Head Knife ×1 is a Lv 14 Blacksmith recipe, 3 steps deep through 5 intermediates, costing 13 units of raw material and 9 crystals.

Handing that in returns 768 EXP and 41 gil for every unit of raw material the order swallows, and the tree needs Blacksmith, Carpenter and Goldsmith.