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The best way is to actually provide an honest reason. Do you want to learn Mac specific software like iMovie because of an interest in creating videos? or Garage Band because of interest in becoming a musician? iMovie and Garage Band are low-cost fantastic starter apps for these things.

Parents are more receptive to practicality, especially when it involves education and productive activities.
 
You already got a new laptop! Either save up until you can buy one or if it breaks down(I know it's not usual but my past 4 laptops before my macbook were incapable of lasting a year) use build quality as a reason to get a mac.
 
Throw a fit! How dare they try to save a few bucks. If they don't run out and get you a Mac right this very minute then they don't care about you!

You need to show them who's boss. Find their credit cards, and sneak down to the Apple Store and get what you want! Hide the Mac until the bill arrives, which will be next month, and by then you won't worry about what they think.

I should be a family counselor.

Legal Disclaimer: I'm just kidding! Do not take me seriously, or ever believe anything I say for that matter, as I am probably lying, except right now, I'm telling the truth, just this once. Be grateful to your parents for trying to do their best for you. Enjoy your brand new Toshiba, and always remember that it was one of the many wonderful things they've given you. There, I've said something nice.

I still should be a family counselor, don't you think?
 
Here's what I did, make a deal with your parents that if you can come up with X amount (Mine was 50% of the cost) they cover the rest. They agreed, then I went further and waited for the back to school sale which saved us money and got me a MBP and a 16 GB ipod Touch ($70 bucks).

Parents love when you show initiative. Don't just ask and expect to receive. Work for it and they'll be impressed.
 
hmmm.
Since they are parents, would suggest try this look :

Code:
http://media.photobucket.com/image/shrek%20cat%20eyes/Amanda-LP/Shrek_2_Cat-eyes_L-01.jpg
 
Here's what I did, make a deal with your parents that if you can come up with X amount (Mine was 50% of the cost) they cover the rest. They agreed, then I went further and waited for the back to school sale which saved us money and got me a MBP and a 16 GB ipod Touch ($70 bucks).

Parents love when you show initiative. Don't just ask and expect to receive. Work for it and they'll be impressed.

Same, offered to pay half of the cost out of pocket.
Then on top of that I decided to wait for the BTS promo so I got myself an iPod Touch and a new printer for the household.
 
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