I just looked at the eBay listing. His buy it now price is a little expensive. But if yoy were interested in having the card before you go, I'd probably big up to $25 on his listing.
If you were to buy a brand new sim card here, the retail prices are ?19,90 with ?8 already included on the sim card. You can buy SIM cards at various places.
Where do you land in Greece? Athens? If so, there's a "ΓΕΡΜΑΝΟΣ / GERMANOS" in the airport who sell the connection packs for the networks as well as the top up cards.
As for unlocked handsets, there's many for sale on eBay etc. Although does anyone else in your household (who's coming to Greece with you) usa GSM (Cingular or T-Mobile), if so, maybe you can unlock their handset.
If we can be of any further help, let us know
