the sony ericsson k850 is officially out and while the iphone replaced my se k790, i think it's time to move on from the iphone. i like a lot of it's features, but it lacks in serious departments IMO. i bought a 4gb model opening weekend and swapped the rear housing so it's completely black. only problem is the ringer/vibrate switch does not work (can be fixed by taking it apart or volume simply turning down the volume of the ringer). since the 4gb models are now discontinued, what would a going used price for the phone be? the rear casing alone is $50 not to mention the install time. thanks!