Good Pets to buy and later resell?

i want some pets that you can buy and later resell to make some money and im wondering what a good pet for that would be. My uncle used to buy baby alligators and sell them a year later for over $100 each and made very good money. I think alligators are illegal pets anymore (correct me if im wrong) so any suggestions on pets that would be good to buy then resell later for some money?