You'll need to replace the bulb within 3 years?
The warranty he's talking about starts when the Manufacturer's warranty ends, so it'd be 4 years from purchase. I don't know that's you'd run through a bulb in that amount of time, but you certainly COULD run through one.
I agree that extended warranties are generally a bad deal, but if they make you feel more comfortable, I say go with the cheapest reputable one you can find, and the bulb replacement IS a nice feature.