Buy mystery boxes (cheap, regular, or expensive). Put it in your home and let your pet open it. Get the item, which varies depending on what kind of box you purchased. Sell it. Note: Sometimes it will not cost more than the price of the mystery box. Repeat this until you have a lot of money, then buy plants. Wait for plants to grow in your garden then sell the grown item. You will get about 50 profit, depending on the size and plant.