The way my daughter did it was to show a great deal of responsibility in other areas of her life, getting good grades, helping around the house, etc. She & I also did a lot of reading about hamsters to get a real handle on how much work they would be, & how much they would cost, food, bedding, etc. She also took care of a friend's hamsters when their family went on spring break last year. I also helped her figure out where we could set up its cage. Finally, after talking about it all summer, a pet store near us had a huge grand reopening sale, with hamsters & their stuff on sale, so she finally got Dad talked into it, too. Now, she (the hamster) is a really fun family pet that we all love very much.