@Richter:
What I want to tell you - if you want something and you show your parents you are working FOR it, I doubt they will say no…
Obviously I don’t know all parents but that is parents for the most part. They’ll help you but you need also to show them you are helping yourself.
You might also show some initiative, do chores without being asked especially stuff your Mom usually does but that you can do to her satisfaction. Especially if she complains about having to do it.
For me helping Mom usually not only got her on board with something I might want but Dad too. When Mom is happy everybody’s happy.