Academic and generalized answer (see last section for final answer):
Insurance is for events that are both
and
Unexpected and Catastrophic Examples:
Unexpected and, for many people, catastrophic events are, for example, sickness, disability, death, car accidents, house fires, and burglaries, for which you may buy health, disability, life, auto, home, and renter's insurance.
Catastrophic but Expected Examples:
It may be catastrophic for a family relying on a very old earner for that earner to die, and you can buy life insurance up to a very old age, but the premiums will reflect the likelihood of someone of that age dying within the covered period.
The more expected an event is, the more anything referred to as insurance is actually forced savings. Health insurance with no copays on regular checkups expects the insured to use them, so the cost of those checkups plus a profit for the insurance company is factored into the premiums ahead of time.
Unexpected but not Catastrophic Examples:
A wooden pencil breaking may be unexpected. Regardless of foreseeability, no one buys insurance on wooden pencils, as the loss of a pencil is not catastrophic.
What is catastrophic can be context dependent. Health-care needs are typically unforeseeable, as you don't know when you'll get sick. For a billionaire, needing health-care, while unforeseeable, the situation would not be catastrophic, and the billionaire can easily self-insure his or her health to the same extent as most caps offered by health insurance companies.
To the Question: Do I buy insurance on a Laptop?
If you're on a fixed budget buying a laptop, if it unexpectedly failed, that would be catastrophic to you, so budgeting in the cost of insurance or an extended warranty while buying your laptop would probably make sense. Especially if you need that $2000 laptop, spending an extra 17.5% would safeguard against you having to come out of pocket and depleting your savings to replace it, even though that brings you to a grand total of $2350 before taxes.
However, if you're in that tight of a situation, I would strongly recommend you to find a less expensive option that would allow you to self-insure. If you found a used laptop for much less (I can even see Apple selling refurbished Macs for less than $1000) you might decide that your budget allows you to self-insure, and you could profit from being careful with your hardware and resolving to cover any issues with it yourself.