I did a stint selling 'maintenance agreements" for a large corporation.
Frankly, I'd recommend learning what all you can by using it for a year & checking bleepingcomputers topic threads during the same period and see if you don't
pay yourself more in the long run.
Take the time to question the parties involved with the warrenties during that time to determine what if any problems develop between you both when communicating. Make it a plan to free up your PC for a short period of time to allow for the real-world posssibility of having to give it up should service be needed.
Pay attention to what you can consider "normal operation" and document it in some way. A brief statement of boot times, sequences, whatever comes to mind that is "typical", can be typed to note or wordpad.
Should a deviation in that norm develop, print your document and detail the change(s).
Save all receipts, and scan them in to that document for easy reference. Include dates.
Consider the investment worth a small percentage of your time spent administering to
the things that for YOU are what you bought it for. Something happens, and most folks
tend to get involved in the problem, not the probablity of remedy. Details of how effective the remedy is (time involved, any expenses and was it complete) tend to be issues in retrospect.
Of course, it might go unused ... that time spent might simply be the records kept on a great PC performer.