It’s because they claim to have stuff in stock which they don’t. The fun starts when they can’t get it quickly from the distributor. I particularily enjoy the random excuse generator- ordered a set of bars from them, 3 weeks later no bars, eventually after many chases they said “It’s because you didn’t specify the colour of the bar”. Only comes in black, ebay item said it was a black bar, with a picture of the bar. Purely coincidence that it was out of stock everywhere 😉
Second time, 2 weeks after ordering a stem, emailed to complain. “It’s because of, er, snow”. And yes it was snowing at the time, it hadn’t been for the 2 weeks before though. Same thing.
Oh, if you leave negative feedback on ebay he tries to bribe you into removing it!