The market sets the rate for onsite computer repair between $50-$100 an hour; those hours are not prorated, so 10 minutes could be 100 bucks, and 3 separate 10 minute repairs could be $300. Cost of a support call will include the time it takes to figure out what the issue is before the actual repair is implemented, not to mention the cost of new parts if necessary. And generally, software problems will take longer to resolve than hardware problems, and there will often be more than one problem. Solutions take time, and when that time adds up to half the cost of a 3yo computer when it was new 3 years ago, it would have been more cost-effective to purchase a new machine than invest repair costs in a machine that could die forever next week with no warranty. You could get lucky, but you could also get screwed. With new hardware under warranty there is less risk of the latter.
I'm responding to the following in your parent comment:
> I expect you mean that you want to repair it yourself, but if you are skilled enough to do that, your time is valuable, so it hasn't been worth your time for at least two decades to spend even 10 hours a year repairing a machine more than about 3 years old.
So your claim about the cost of onsite repair is completely irrelevant. We're talking about the cost of repairing something yourself, which you very frequently can do, even when you're working with something as unrepairable as a Macbook.
