Yes plenty of scam sellers on ebay, if you don't know what you are doing you will get burnt....
I have bought a few Sandisk flash drives, Sd cards etc from the seller, all genuine in original packaging, full capacity and speed. Absolutely no doubt in my mind they are genuine.
Just ordered 2 more micro Sd 32gb class 10 45mb/s Transcend at R146 a pop. The sandisk class 10 at the same price are 30mbs so I went with transcend this time, wait just checked now the sandisks are R135 now. The sellers I've used are courtesytrading and sinceritytrading. They normally come shipped in a very small padded envelope so often arrive without duties payable.
The 64gb of either of the variations I've mentioned above are around R280, all incl free shipping.