When I busted my passenger mirror, I got an OEM one off eBay. My other suggestion would be moparonlineparts.com. Their site sucks, but it's cheapest place I've found yet. Maybe hit CL for someone who's parting one out?
Oh, and lastly, if you can't find it in your color, buy yourself a small spray can of automotive primer (and make sure it's automotive), and then search around here (I posted in the vendor section recently asking about DaBears2k, which is worth looking at. My laziness prevents a link though, sorry) for a place to buy a spray can of your car's stock paint. Having done this, locate a friend who's good with spray painting things, and trade them a six pack of beer for the spray painting. Worked great for me.
Warning: The above post probably contains 2 or 3 times as many words as necessary.
2005 SXT AWD. Purchased in March of 2009. Totaled on January 16th, 2013. 75k excellent miles together.
1982 Isuzu I-Mark Diesel. Haphazardly acquired January 2010.
1981 Honda Twinstar. Salvaged from my backyard in 2009.
2006 Volvo S60R. Acquired Feb 1st, 2012.
1966 Ford F100. Acquired March 30th, 2012.