Exotic bullies are often seen as a bad investment because they are a relatively new breed that hasn't been fully established yet.They also have a number of health issues that can be costly to treat, and their popularity is tied to passing fads and trends that can quickly fade away.
Additionally, they can be expensive to purchase and maintain. Ultimately, whether or not an exotic bully is a good investment depends on your goals, and whether or not you are willing to take on some risks and challenges in order to own one.
Just keep in mind the price you pay for the Exotic,the price you pay to up keep it e.g. vet bills, food bill etc and what you'll actually make if your exotic could produce to cover those expenses.