How to convince parents to get me a hedgehog?

Over the past 2 years I have kept exotic pets that my parents bought for me or that I had caught. Some pets are a tarantula and 3 ant colony that I've raised myself. I have enough money to buy a hedgehog and I know a breeder. I have cat kibble that I will feed it and I have money to buy it. I have a Tupperware container to house it in and I'm going to purchase a wheel. But I'm pretty sure they will say no. I have proven myself responsible to them by now I think. I've already asked a year ago and they said no. What points can I bring up to them to help my case? I have done much research and I even got my English teacher, who has a hedgehog give me some pointer on how to take care of one.