How do i convince my mom to get me a cat?

We used to have a cat and she died. My mom said she loved her but she was ALOT of work. she thinks that she'll just have to end up cleaning after the cat. Plus my brother is allergic to cats and i cant find any cheap, at most 1 hour away(i live in buffalo,NY), hypo-allergenic cats. im only 9 and i dont celebrate any holidays (including birthday). any ideas of where i can find a cat that fits the details and how to convince my mom? thnx