Quality control is a real issue with re-sellers on eBay and Amazon. You don't know whether the item for sale at an inflated price is genuine or knock-off, new or used. Who wants risk paying $15 for a used or fake mask?
The whole purpose of Ebay originally was that sellers were reviewed accurately by buyers. And if they had a lot of positive reviews they were trusted. So perhaps Ebay is deleting the ones with lower or little ratings ? There are people out here that need masks, are not government or frontline workers, and our work causes many others to gain income.