I'm on the downward slope of my own challenge, which is to get rich without using a single simoleon cheat. I made her a werewolf, with the gatherer trait, saved all her simoleons, and invested in all the local businesses. If you have Seasons, it's a little easier, because of picking and selling wildflowers.
That might be a way to make the game fun. Or you could try and get a male character pregnant with an alien baby.