Slow Flash Card Access Small Files Genuine Or Fake Compact Flash Card?

Genuine or Fake Compact Flash Card? - slow flash card access small files

I want 4GB SanDisk Extreme III CompactFlash card. On eBay, and some pages on Google are selling about 100 pounds, but Jessops double. I read that many sites selling fake CF cards, but slowly, budget 4GB card and the implementation of these caro Lables Scandisk in them. How do I know if I have a fake card, and therefore my credit card or Paypall give me my money? Is there any software that queries the chip card and tells you exactly what it is, and therefore an original? Thank you for the advice ...