I agree w/ Lander, unless if you're buying a real inexpensive system that you will anyways want to upgrade in a year or two.
Whose warranty is it? We can look that up. The plan should cover the cracked screen, in case you accidentally drop it, and anything else that happens from accidental blow-- the screen's as much as a G right there...if for some reason your battery goes-- that's half the cost of the plan. If a power surge fries you're..you're covered up to the dollar amount stated.
It should state that you will get a replacement laptop if not able to repair it, but should not limit that value to something much lower than the price you paid, nor should it state that if not able to repair they have the option to just return your warranty payment & that's it. Does it include Express Repair? Is the plan transferrable?
It really depends a lot on whose plan it is & how advanced the system... and keep in mind who will replace it in case of loss or theft: homeowner, renter, vehicle insurance..... Will you need a device to affix it to something? Keep in mind the anti-theft software also...