About this, and anyone else having issues with money, the easy way to handle this issue is with the milkers, as they give more money for quantity of liquids, with most peoples' problems being getting the liquid amount high enough to make a decent profit. The easy way to solve this is to basically enslave a couple of demons, and if you're like me you just enchant their clothing to enslave them after beating them. Then you go to their transformations and order them to produce the maximum amount of cum and lactation, and then dump them into whatever milker rooms you have 24/7. Don't bother upgrading rooms, they won't ever be there, and if you want to gain affection while doing it give them the Cum Stud and Lactation fetishes by enchanting the Mystery Kink potion.
TL;DR: Kidnap some demons, make them shoot out as much milk and cum as possible, and stick them in the milker for maximum profit. As a side note, technically the price for the liquid changes with qualitative effects added, albeit I'm not sure by how much. Also, this only has to be done once. If you're looking only for money pumpers, export the current one and then import them back for infinite milk bags.
EDIT: Comparitive profits of slave jobs. Note that giving this slave most kinks is just something I did.
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