France
Summer 2018 I was traveling to Paris a couple times and looked into buying a sim card in Paris. Just last weekend (February 2019) I visited Paris again and double checked the prices for sim cards at Paris Airport for you. Again I was surprised that buying a prepaid sim card in France is not as expensive as in other European countries like Germany and Netherlands. In the city center of Paris there are actually a couple European sim card options for tourists available, but I was also curious about buying a sim card at Paris Airport.
Before this trip to Paris I always used to joke about the fact that I grew up about 2,5 hours from Paris, but had never been there. My most visited city is probably Bangkok with 15 times and until last November I also had never been to London either. Traveling in Europe is not really on my bucketlist as I have been to most of the countries and the destinations are kind of too standard for me. I will visit these cities when I am 60 I always say. Right now I rather sit in a dodgy little bus crossing the cheap countries in Central America or something like that.
Just like me you are going to be one of the millions of foreigners who visit France every month. Most of us are going to Paris and all of us take pictures with the Eiffel Tower. It is a common thing to do and we love sharing our travels online. So in order to avoid crazy roaming costs in France the best thing to do is to buy a prepaid sim card in France with data.