I would like to get one for a birthday but my parents what to know if it's a good idea or not.

You can direct them to the 2 'stickies' at the top of this board, and they can also read some random questions about piercings asked recently (and of course you read them too). Meanwhile you could find out who is a licensed practitioner near your home, and ask around about their reputation from classmates.

It's really a family/personal decision. I believe it is suitable. If you really want one, you can try giving them some good facts about those piercings.
Lots of 13-year-olds have them
It hurts less than a lobe piercing due to less nerves
It sometimes costs less as well
You can always remove it.

Lots of 13 year old and teens have cartilage piercing. I also really want one 2 but my mom says no. But I think its OK. Look is a big way to describe yourself besides how you act .And its not like your asking for 50 piercings.