I just bought my 2005 Pathfinder, used. To get a "Wrap" policy to 100,000 miles or 84 months from service date, was $1000.
I have also heard that some of the aftermarket warranties (i.e. WarrantyDirect.com) are pretty affordable.
I know that I will either trade-in or get an aftermarket warranty at the end of mine. I just had a fuel level sensor die ($400 job) and rattling timing chain tensioner (6 hours of labor + parts), which were both covered by warranty. My sentra's engine blew up at 80K, covered by warranty.
So, from where I stand, warranties are worth it.