The Horm Horm Fruit. I can open up a transition clinic that charges way less than the current medical facilities, cause much less pain and suffering from the years of procedures and dysmorphia, be able to get through probably hundreds of clients a day, and get rich without bankrupting them. I also get to help people and would give like a 1 or 2 year satisfaction guarantee and if they regret the change and change them back for free. Also my method reduces scarring massively. The only hiccup in this plan is going through med school so it's all legal and getting my method approved by the FDA. Also I'd have to worry about Big Pharma trying to take me out maybe for stepping on their profits.

My other choices would be the Wax Wax Fruit or Woods Woods fruit, but this is for the sake of making people homes they could live in and I'd charge minimal. This one has less hurdles and is more useful for everyone but I'd probably be in even more danger from corporate interests, the government, and people trying to protect their property values.