I\'m trying to set up Schema.org metadata on a site at the moment, and I\'m wondering how (or if) to declare multiple currencies. I have 6 formats of the price - GBP, USD and EU
It's really the Offer that has a price associated with it. If you look at the second example on the Offer schema page, you'll see multiple offers associated with a single product. They're from different sellers (and don't specify the price in a machine readable way), but you could do the same thing with multiple offers in different currencies from the same seller.
I'm not sure there is a way to express inclusive or exclusive of VAT in the schema, so you may be stuck with just text labels for that.