Hoarding violins and high-quality harvestables to raise bills if you play vanilla, or modify bills with a mod. Or just nuke your savings with money cheats.
I ran into trouble since I tend to make a lot of money quickly due to my habit of quickly finishing off the fortune aspirations and Frugal saving me all the money in the world. :sob: Since frugal stacks, it's a bit upsetting that I don't pay more than 36k for a mansion. But I'm just going to wait till the frugal sims in the house die and the children drown in debt... Over time, of course. :/
I wish there were more expensive things to blow money on in TS4 as well. Taking an obnoxious amount of vacations and staying at an expensive cabin isn't really taking away much money either. :(