Ah, thank you very much!
The cards sold by outside vendors are doing the postage scam. It's them I complained to Amazon about, and them they fobbed me off about. I'm now going to reply to their complaint response...
The card I had looked at on Amazon was a 2GB one for £0.38. Which is taking the postage thing to extremes.
http://www.amazon.co.uk/Transcend-Fl...6182763&sr=1-1