Not sure what the reasoning was with the rewards here but it's not balancing out too well.

You get two FATEs worth of seals if you HQ these, one and a half if it's NQ. That's it.

Do I spend thousands on high level materials and shards or alternatively spend about an hour gathering the materials myself, or do I head over to Northern Thanalan and fire off 3 AoE spells?

Personally I do them for the achievements. I have no choice or the voices in my head get mean. Just a thorn in my side that it's costing me to quest. What if you came across this when you leveled up: "I'm in need of an adventurer to put down some mongrels. Pay me 5000 gil and I'll let you be the one". No thanks, don't think so.