Buy a home and insure it is the type that holds the wooden frames on the walls where you can place trophies. Next, mount two trophies on those frames. (The better the trophy, the faster you will become rich.). Once you've mounted your trophies, go back outside to the sign, and sell your house.

By placing trophies in the house, the sale value is greater than the house's construction cost, thus the profit. But the trophies are still in the house. Simply break down the doorway (hence the reason for choosing the design with the wood doors) and simply grab the trophies to devalue the house. Buy the house afterwards and re-install the trophies. As long as your character does not leave town, the broken down door remains and you may repeat this process and profit from the buy/sell difference to gain money.