It happened to one of my friend's as well, he really lucked out because the company who sourced his original window gave him a replacement under warranty! When I tried that approach, I was offered a 10% discount. Better than nothing, but I ended up going with a used one out of the Tulsa area. I love road trips anyway, and the drive out was gorgeous (even without the back window) and I ended up meeting and talking with 2 very amazing people.
The gentleman who sold me the glass, bought his first jeep, an immaculate 2003 TJ with only 60k on the odo. Only mods were 31" tires and leather seats. He was an Army Vietnam veteran with some amazing stories.
On the way home I stopped by Sedan Kansas at the Gunnar's Bourbon Distillary, had a wonderful bison burger and an amazing conversation with a gentleman who worked as a street preacher, a missionary and artist. Also, they make good wheated bourbon. I'm looking forward to heading back to Sedan to take the tour.
It's really cool how a crap situation of losing the window turned into a cool opportunity to meet some really interesting guys.