There are a number of different ways to book Eurostar depending on where you live, where you are travelling and what currency you wish to pay in.
Eurostar.com if you are in the UK these will be priced in GBP, there also International Options to book in your local currency. To get the best fares it is worth playing around with the site and currency REMEMBERING that if you pay in a different currency to you card you may incur additional charges.
The Eurostar website eurostar.com allows booking onto Eurostar’s direct trains to/from the UK and Calais, Lille, Brussels, Paris, Lyon, Avignon, Marseilles, Disneyland Paris and ski resorts in winter. It also enable through tickets to/from be booked to:
Belgium: Every Belgian Station
France: 79 destinations
Germany: Aachen, Bonn, Cologne, Dusseldorf, Frankfurt and Munich
Netherlands: Amsterdam and Rotterdam, plus Schiphol Airport
Switzerland: Basel, Bern, Geneva, Lausanne and Zurich
Destinations with approximate journey times: eurostar-connections-journey-times–6ukc3olvl8
This site prices in Euros and offers fares throughout Europe.
This site is useful when booking through journeys to/from Germany.