I take it to get an 8gb memory stick for €30 you are buying from the Far East.
Well I'm sorry but I wouldn't take the risk.
I have been using eBay for 8 years and the increase int he amount of people getting scammed over recent months is frightening. I bought a 4gb stick last year and it turned out it was branded as 4gb but it was a 128mb chip on it. Could not get a reply from the seller.
Also a mate of mine recently was scammed out of £800+ on eBay for a laptop.
You need to be very careful on eBay these days, and I don't think I'd buy anything from the Far East again.