Make a Fish
Location
Required Items
Rewards
What the allowance actually buys
One allowance here buys 420,159 EXP, which places it 3rd of the 4 Lv 40 Fisher fieldcraft leves that record EXP — a figure 1 other leve on the rung matches exactly. The best of them, Empire Builder, returns 700,265 EXP for the same allowance, 67% more.
On whether to wait: the best Lv 45 Fisher fieldcraft leve returns 916,282 EXP per allowance, 31% more than the best on this rung, while the Lv 35 rung behind tops out at 472,989 EXP.
At Lv 40 this data holds 52 leves paying EXP across 2 categories: the 4 Fieldcraft ones average 560,212 EXP per allowance, the 48 Tradecraft ones 72,545 EXP, which puts this leve 25% below its own category's average.
Nothing on the turn-in list is craftable in this data: Abalathian Smelt ×3 has no recipe here, so 3 units must come from gathering, a vendor or a drop.
The record carries a repeats value of 2. This site reads that as 2 further turn-ins on the same leve — an assumption, because the source data defines no meaning for the field — which would put the ceiling at 1,260,477 EXP and 780 gil for the 1 allowance it costs, or 1,260,477 EXP per allowance.