I really fail to understand how people are having trouble with this.
I just tested out a game while making the absolute worst possible choices, and still had zero problems with the loan.
That is to say - making balanced characters from both the MC and the initial slave, focusing on making coin through crafting/prostitution and ignoring the quests/combat (which are by far the most rewarding choice at the start).
The one potential problem is if you have low charm, and don't get a secondary character to help keep up obedience (though that's easily soled by a dancer, maid, etc.), but that doesn't seem to be the issue people are complaining about.
You can make more than enough gold/day with just 3-4 slaves dedicated to making gold through something like cooking meat soup (and I guess farming meat/vegetables) . This is not really a good idea, as just farming goblin cave/bandit den/forts and harvesting them should produce much more gold and xp per turn.