If you're going to Deauville you'd be better to fork out the £15 for a taxi ride into Honfleur: Lovely old mediaeval port with reasonable proper French restaurants scattered around it and narrow cobbled streets. There is also a supermarket where you can stock up on wine etc to offset some of the cost of the trip. There is no shop on the airfield unless you are going to the Channel Isles, when you can get duty free. (At least that was the situation when I was there in December.)
Expect to be asked to report at the bridge over the Seine (Pont de Normandie) as a VRP. Good ATC service from crossing the French boundary and it's not REALLY that far single-engined across water!
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"Take-off is optional, Landing is mandatory"