Depends on how long you kept running it after you heard it making those "Sumpin' ain't raht" noises. Master sh2sh2 explains:
If you open the door is there sharp metal at the top of the opening, if so the 400 dollar estimate is correct.
What happens is the slides wear away and start making noise and if you dont fix it right away the drum wears through the plastic bearing holder and starts making more noise, then if you dont fix it then the drum starts eating through the metal of the front panal.
I have actually seen people not call for service untill the drum starts wearing a hole into the door itself and eventualy jams the drum so the dryer finaly stops working. By that time its too late to save.
Buy parts for your GE dryer here ==> http://www.repairclinic.com/GE-Dryer-Parts