I'm never comfortable with a 1 year warranty for a multi-thousand dollar projector. (OK, I can understand shorter warranties on under $1000 products). That's just tempting Murphy and his law. If your projector drops dead in its 13th month, with no warranty, that's going to be a real expensive bummer. At least, with two year warranties, if your projector breaks in month 25, there will be much better projectors than the one you are buying, selling for a good bit less.
Although not a big fan of third party warranties, in most cases, I do think getting at least one year extra, is a good idea when you start with just a one year warranty. Hey, it's a tough call.
Pay attention though, some dealers seriously overcharge for those extended warranties. (Usually the ones selling the projector for below their cost, but who will only sell it to you if you buy an overpriced extended warranty)