These cards have been apearing on Yahoo for almost a decade. They pop up a few times a year at random. Most people either don’t want to take the risk or never catch them in time. Auctions always end in a 3 days w/ 48 hrs to pay. So they usually sell way below market because of the hassle.
There’s always been these random chance encounter deals on yahoo. Like the Japanese E series samples from early 2010s & the proto birds that Linkdu acquired.