I ordered the dryer drum drive belt, interlock switch, and door switch. Upon disassembling the dryer, it was clearly a snapped drum drive belt (the factory belt is thinner and probably less durable than the replacement belt). I replaced the belt and the switches to boot in under an hour. Parts and next day shipping under $100, which is what I would have paid for the factory service guy to come out in two weeks, before parts and labor to actually fix anything.
The instruction videos didn't mention it, but there are some square drive screws in my particular GE dryer. I had an appropriate driver on hand, but it would have been annoying to need to find one at a hardware store on a holiday.