I've been trying to talk my parents into getting another.
Best way to convince is IMHO that you can show you can pay for everything and care for it on your own.
Yes, I know, this awfully sounds like "parent", but no, I don't have kids. It's just the strategy that worked well with my parents. (And it was not a rare occasion that when I showed that I can come up with the money - miracle, miracle, suddenly at least a part of it was a gift from them. Same when I showed I do the chores, and other things that are not really a favorite - miracle, miracle, suddenly there was help with it
)