What Currencies does Google base support?

Well i sell the licence in (GBP) Great British Pounds Sterling, but the feed doesnt work in currency, it just sends the raw number of money. So for example if i have the licence in the feed that is £29.99, then it will show as <price>29.99</price> in the feed and have no reference of currency.

Google then displays the currency that is either set in your Google Merchant Account or the currency used in the targeted country, which for me would be GBP, or if my website was targeted to the United States it would be (USD).

This cant be passed through the feed anymore like the good old days.