it doesn't work quite so good since the change to how levels work but there's a stratagem that reliably allows me to make the first two payments relying on two characters without needing to do rep quests or dungeons at all even, i call it the "Nearest Green Trick" inside my head, because it's just "make whiskey=> sell => profit" even if you have to buy grain
1) farmer slave - typically a human (dryads are better but rare spawns) slave with high phy, send them out to gather grain, get them the "farmer" job asap, make sure they don't have any negative traits that hurt farming
2) cook - usually an elf or (even better) a (half-)tanuki with high wit (and ideally the craft +20%" trait), park them at home and have the craft whiskey (set to infinite, and just drag an order for meat soup or whatever over the top when you want to stock inventory for food-to-use)
if your cook runs ahead of your farmer you might need to buy supplemental grain from the market, and usually by the time you can build the "gather grain" upgrade the farmer's obedience drain will be so slow you can probably just leave them deployed indefinitely
negative traits that affect other jobs (like that coward one that cuts hit rate 50% or the anti-sex ones) are actually good for these characters, because they lower the purchase price and are irrelevant to their jobs, so it gives your budget more breathing room to buy other slaves as part of the dungeon squad or whatever
there are variations on what you can do with the cook, "apprentice" is usually a solid move too because wit+10 helps with cooking & is part of an actual class progression tree to keep them useful after the first month, although "apprentice"+"cook"+"alchemist" is usually a pretty solid end goal for them because they can house-sit, making food or magic items, and then also use the apprentice hypno-magics to manage other, newer / less tame slaves; a peon usually works better than a slave for that later stuff, but it doesn't matter if the cook is a slave or a peon as far as this stratagem is concerned
although, that said, it is very funny that the prologue is easily the hardest part of the game, where you have to rapidly make decisive decisions so you don't get trapped in a doom spiral that sends you swirling down the drain to a game over, unlike the entire rest of the game where you can all the time in the world to progress a quest