According to Vodafone Malta and the “iPhone 3G/3GS in Malta”-Facebook group, Vodafone Malta now has the 16GB iPhone 3GS available and in stock. You may have to go to Dickens in Sliema to get one though, I’m not sure yet.
The list price is €599 but they also write “Special offer price: €75” – not sure exactly what that includes, could be for business plans only. I do believe, however, that the €599 price is without contract – but probably still simlocked, expect prices to be as high as €200 to have it unlocked (for the 3G at least, probably the same with the 3GS).
Personal price plans ranges from €40 a month to €100 a month – for 24 months (!!!) – including minutes, text and data.