After posting the above message, I remembered that my city's best delicatessen has a selection of non-Swiss chocolate so I stopped by this evening. There weren't actually lines forming in front of the shelf but they in fact do have quite a selection of Valrhona available.
I picked up two 75 g bars, one a 70 % cocoa "Guanaja", the other a 40 % cocoa milk chocolate "Jivara". The cashier gave me one of those "Are you nuts ?" looks when I plonked down $ 4.50 for the two small bars but I bravely went through buying my first non-Swiss chocolate in Switzerland.
I still have some very good Swiss supermarket 73 % cocoa at home that costs less than a quarter and will do a little chocolate tasting and comparing for dessert tonight and report the results.