Seems E-bay is now full of sellers from Hong Kong selling various technical items for about half of the typical price, sometimes less. The sellers have 50-300 positive feedback score with account opened for the last 6 month to a year. Then they suddenly list a lot of items for a good price and sell dozens of each quickly. After some time they stop selling, make their feedback private, and that is when negative feedback numbers start to shoot up. They do ship something to generate tracking information, but I think it is an empty envelope sent to a different address. Sometimes it's obvious from tracking, sometimes they pick an address in the same zip code. Then E-bay says the item has been delivered.
So far I have been burned twice, and even though I got my money back, it may not always work out this way. So if you see a good bargain from a seller which fits the above description - be aware.