If like the writer you can't help but do some 'window shopping' for property whenever you visit a new place, you may be interested in this brief summary of the local market. (Buying property in France is very different to buying in other countries and you should not do anything without fully understanding what you are doing and, where appropriate, getting proper legal advice).
Royan and the immediate area does not have a history of wealth (before 1900 the main source of income was fishing and producing oysters) and consequently there is a very limited stock of really old property of the type that you will find in much of rural France. During the 1950's and 1960's there was an expansion of building but much of it was of questionable quality due to the lack of effective building standards.
More recently many attractive villa style properties have been built around Royan and in nearby villages such as St Sulpice de Royan and Breuillet in compliance with much more stringent building regulations as regards the type of construction, insulation and services etc. (New homes in France normally come with a 10 year guarantee). The are many advantages to a village property including a greater sense of 'real France' for example being able to saunter to the boulangerie for the morning's croissants, more opportunity for 'year round' living - Royan itself becomes very very quiet during the winter months in comparison to the summer- and at the same time the avoidance of the crowds during the height of the summer.
Much of the property in the centre of Royan is either purpose built appartments or larger houses that have been converted to appartments with most being let on a weekly basis. Along the seafront at Royan and also in Pontaillac and St Palais there are some utterly gorgeous Belle Epoch villas that survived the bombing during the second world war. Unfortunately they have prices to match!
The demand for property is driven by the desire for second homes in a renown holiday destination (particularly by the French themselves) and also for people seeking a permanent home by the seaside moving away from large cities. As a consequence prices are relatively high by French standards and in particular prices rise as you move closer to the coast.