My first IEMs were the Shure SE215, they cost me about the same as an Aria. They didn't sound that good compared to what's out there now but they lasted me half a decade of hard use, and still worked perfectly when I sold them. It's absolutely a QC issue, or if you prefer, a TQM issue. Inexpensive IEMs can still be durable, and letting manufacturers think it's okay for IEMs to be "wear items" is only doing a disservice to ourselves as consumers.