How to convince my parents to get me a pet bunny?

Well, so far i have 1 dog, 2 sugar gliders, 1 flying squirrel, 3 cats, 4 kittens (which we r giving to the shelter), and 2 newts. I really want a bunny. I seen them in the pet store and I thought they were really cute and I held one and it snuggled into my neck and i heard they're intelligent and can be litter trained so I asked if I could have one and I'll pay for it because they're only 27 dollars and I'll biuld it a cage for wehn I'm gone and I'll buy the food but they said I already have to many animals. I really want one and i will pay for it. How do i convince them to let me get one?