My ex did it. Pretty simple with apple finance.
It is an extremely bad financial decision though.
Computers are a very quickly depreciating asset. They're bad enough to buy cash, if you're financing over say 3 years and adding 40% to the long term cost, well... you're throwing money away at a vast rate of knots.
If you do finance, buy the lowest spec you can get away with (Try to get a re-furb) and don't buy upgrades from apple. In addition to being expensive you'll be paying 1.4-1.5x the sticker amount over the finance period.
I'd suggest downloading a loan calculator spreadsheet (or use the one in Numbers), plug in the numbers and work out how much the machine will cost you over the repayment period. If you can avoid financing even SOME of it, pay everything you can now as you'll save money in the long run - every dollar you don't have to finance will save say $1.50 after 3 years.
You're definitely better off saving the money and buying it that way.
Interest free periods do change it a bit, but bear in mind that often a lot of the "interest free for 12 months" loans have a killer interest rate AFTER the interest free period (like 2-3x the regular rate - this is where they make their money!). Make sure you pay it out before the interest free period ends!
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You save money from buying brand new cars from repairs, warrantees and through not being required to pay for an MOT each year (in the UK), not to mention newer engines have better fuel consumption, so sometimes financing a new car is a sound decision.
Depends how old you go. If you're buying 20 year old POS then of course.
However... not sure on the UK market, but here in Australia a lot of cars depreciate by say 50% over 3-5 years.
After 3-5 years plenty are still perfectly roadworthy, reliable, etc. And fuel economy hasn't changed THAT much in the last 5 years.
On say, a $40,000 car, saving $20,000 (even more if it means you don't need to finance it all or as much) pays for a lot of maintenance (that MAY or may not be requried), additional fuel consumption or other more important things. Such as say, getting further ahead on your mortgage...
Bear in mind we don't have snow and so no salt on the roads, so our cars do tend to last a lot longer.
But of course, everyone wants teh new shiny!