Nimh approved this business plan!
Ieffreon population: 30,000
Competitors: multiple
Assuming that persons outside of Ieffreon also eat fish

then the competitors / population number is not the biggest factor. Larger factors are fish availability + weather. This is easily remedies (or fixed) by spells and Ieffreon's usually-bright-and-happy climate.
Types of fish common around Ieffreon: bluefish, groupers, sardines, herring, tuna, mackerel
Types of fish Straylor can magically lure: all of the above
Average catch: According to this moderated by AGM Tux, Straylor can 'fill the nets completely' with about four 'charges' of a Level 3 Attract-Fish spell.
http://www.playbypost.com/forums/ieffre...private-2.html
Assuming that each of those carracks have comparable storage to the ships AGM Tux employed during Straylor's first stint (it wasn't specific) Straylor will be able to get approx. 2 tons of catch per ship.
Average profit per ton: 200 crowns
Average number of fishing trips per cycle: 4 (if I were cruel and evil I'd make them go fishing every damn day of the week!

)
Average Income per month: 200 crowns x 2 tons x 4 ships x 4 times per cycle x 5 cycles = 32,000 per month
Expenses: According to letter here:
http://www.playbypost.com/forums/trysva...ml#post1342650
380 crowns for supplies (95 crowns per ship) per cycle
250 docking fees x 4 ships per cycle = 1000
Crew costs:
35 crowns per cycle x 76 crewmen = 2660
70 crowns per cycle x 4 captains = 280
Total Expenses per month: 21,600 crowns
Total PROFITS: 32,000 - 21,600 =
10,400
*NOTE: to 'ensure' this amount Straylor will have to either produce enchantments to create a perpetual magical lure, like a signal, on his ships OR provide glass globes which must be deployed half a candlemark before throwing down the nets for maximum advantage (again, this is based on what Straylor has RP'd before).
So, glass globes required per trip is 3 globes x 4 ships x (on average) 4 times per cycle x 5 cycle per month = 240 charges of the 'Fish Luring Spell' of the journeyman level.