If one only cares about reaching a money goal and not a constant money influx, what about collecting metals and making compendium?.
To the point: if one places 8 metal (need more than 1 type, but less than 5 or you'll get supernovium) ingots in the xl case and click on irreversible transfigurification, you get an ingot of compendium. Compendium's value is uncapped, and is equal to the sum of the values of the metals used + 25%.
You can make compendium with other compendium.
If a sim can provide a constant influx of metal ingots, it can make a super compendium ingot worth (current compendium + value of picked up metals) * 1.25 per transfigurification. This ingot's value will grow exponentially; even with very low value metals and making only one compendium per day, you can max the game's money limit within 30 sim days; with half-decent ingots, it can be reached within 2-3 sim weeks.