I Saw What You Did There

One allowance here buys 47,200 EXP, the best on the Lv 25 Blacksmith tradecraft rung — matched exactly by 1 other leve of the 6 there, with the rest trailing at 36,390 EXP or less.

Across that rung the return runs from 21,830 EXP to 47,200 EXP per allowance — 4 distinct figures spanning 116%, so the wrong pick leaves 25,370 EXP of the allowance unspent.

On whether to wait: the best Lv 30 Blacksmith tradecraft leve returns 67,730 EXP per allowance, 43% more than the best on this rung, while the Lv 20 rung behind tops out at 21,600 EXP.

At Lv 25 this data holds 52 leves paying EXP across 2 categories: the 48 Tradecraft ones average 31,772 EXP per allowance, the 4 Fieldcraft ones 204,269 EXP, which puts this leve 49% above its own category's average.

Iron Chocobotail Saw ×1 is a Lv 28 Blacksmith recipe, 3 steps deep through 4 intermediates, costing 12 units of raw material and 11 crystals.

Handing that in returns 3,933 EXP and 45 gil for every unit of raw material the order swallows, and the tree needs Blacksmith, Carpenter and Goldsmith.