How should I ask permission for a mac?

Before answering, keep this in mind:
- I'm not asking my parents to buy me a mac. I have saved money for this and have been wanting to upgrade my computer for a while. It's a mac mini, so they aren't concerned about my responsibility w/ the mac [ie: had I bought a macbook where I could potentially lose it]. Money also isn't a pressing issue, (my parents have iPhones).
- I intend to buy a mac for Logic Pro and the ease of use w/ the operating system. Trust me, I have considered other audio production tools from FL studios to Pro Tools, but after reviews and watching videos of them in use plus recommendations from teachers and friends, I have found Logic the best to suite my needs. If you are here to detest the macs, I suggest you leave.
- I will not lose anything switching to a mac. I mostly use my current computer for mundane tasks like word processors, iTunes, email, small video projects, etc. All of which will be included on the mac os. Logic will be the first professional software I use. I do not play computer games. The specs will also be an upgrade from my old computer.
- I'm familiar with the os [my school has macs that I have worked on for a music class].
So I have discussed all of the following points with my parents, but they still are reluctant to give me permission. A hackintosh is out of the question because they are concerned I would break the computer [and to be frank, I don't trust myself either]. Should I bring up anything else?

Take a few well-planned steps…

First, ask them if you can buy a rocket propelled grenade launcher. Give them a long, detailed explanation of how an RPG launcher can be a big boost to your tactical skills development just in case you join a militia group in Montana or Michigan.

The next day, ask if you can buy an elephant gun to go on a safari in Mozambique. Do the whole arguing routine again.

The third day ask for the Mac. They should see this is the least destructive and least violent option and agree.

If your parents think like my oldest brother ("Global warming is fake, GW Bush was a god, Apple is from hell"), they will tell you to buy the RPG launcher.

Make them feel like this purchase is 100% worth it. Compare it to other apple products of higher prices, but not as good specs (ex Macbook air having worse specs than pro, stuff like that). That usually gets them to cave. I bought a surface pro 3 (today) from my dad, and after convincing him it was extremely cheaperr than a Lenovo Yoga Pro 2, He bought me one, and is considering one for himself too xD Good luck brother with your purchase!

Are you buying it with your money? If so it is very expensive for what you plan on doing. You will need a MAC PRO for the software to perform well. That costs 3k, for 3k I can get a heck of a PC with adobe audition for much less and it can perform the same with a different OS. I would honestly recommend Linux. I think there's a distro for audio editing.

Uh, what's the risk with a hackintosh? It costs less than a Mac, is more versatile, and it gives you everything you want/need. Breaking a computer turning it into a hackintosh? What's to break? It's not like you could actually break anything doing that. All you have to do is pick hardware which has been confirmed as usable. Everything is laid out for you after that.