As they are now they are a noob trap to punish players that don't know any better.

Fishing for Profits (Large Scale) = 3x cedar fishing rods for 245k exp (490k total for HQ) with 22 ice crystals

Landing the Big One (Regular Leve) = 1x cedar fishing rod for 120k (240k for HQ) and 16 ice crystals

You actually get more experience and crystals(720k total experience and 48 crystals for 3 allowances vs. 490k exp and 22 ice crystals for 10 allowances) doing the single leves than you get doing the large scale leve. I understand that in order to promote the collectable system SE might not want large scale leves giving out something silly like a million exp or something, if that's the case, just remove them from the game entirely. As they are now, they are just there to trap players into wasting their allowances and materials turning in the same items for a smaller reward.