♥ Offer to pay for half. If you don't have to money, just take a few babysitting jobs or something.
♥ If you say danger is the main issue, tell them that you can get it with safety nets. They really help, I would have fallen off a million times if it weren't for those nets.
♥ Promise not to do any flips of any kind. Sure, they're fun, but there is a ton of other fun stuff you can also do on the trampoline. Just be creative.
♥ If you buy a net and don't do flips, there really isn't a lot of danger. You can't fall off, you can't paralyze your neck. The worst that could probably happen is that you run into someone else and get a few bruises.
♥ Of course, there is still a small chance of something really bad happening. But you also take that chance when you walk, get in a car, fly, bike, etc....