well, I haven't been doing many of late. maybe 20 quests in the last 3 weeks.
120 fishing scrolls net 20-25 mil a pop.
special baits are hot for the rare fish.. 3-5 mil per easy depending on which one.
spyglass slow, slow, slow to sell. 25 ish mil maybe 35 if you dont mind waiting for a long time.
No automation
Must have a new high seas boat or else you wont be able to fit the orders in the cargo hold once they get large.