Yes, there is a duty-free shopping experience available for Eurostar passengers at Paris Gare du Nord, but it functions differently than a typical airport setup. Since the United Kingdom left the European Union, "tax-free" shopping has returned for travelers moving between the UK and the EU. After you clear French customs and British passport control within the Eurostar terminal, you will find a dedicated "Relay" or "Duty Free" shop in the departure lounge. Here, you can purchase spirits, wine, tobacco, perfumes, and luxury cosmetics at duty-free prices. It is important to note that the selection is significantly smaller than what you would find at Charles de Gaulle Airport, but it covers the essentials. Additionally, travelers who have made high-value purchases in Paris before arriving at the station can use the "PABLO" tax-refund kiosks located just before the customs area to claim back the VAT (Value Added Tax). Because you are entering the UK, you must still adhere to the standard UK customs allowances for alcohol and tobacco to avoid paying extra duties upon arrival at London St. Pancras.