Only time will tell if it's a string of bad luck. I understand your frustration. Could be each of those sellers have items listed on multiple platforms and they "forget" if it has sold and they forgot to take down the listing. I've never had so much inventory that I couldn't manage it properly. 'Don't list what you can't easily touch'. It's elemental. It's kind of insane to "lose" or "misplace" an item for sale. I rarely deal with Discogs. At least (in my estimation) eBay has an inclination toward the buyer insofar at rectifying transactions such as this.