These little and strongly flavored fruits are not grown industrially and they're therefore difficult to come by. They grow in the mountainous regions, high altitude forests and the like, and if you find them for sale in markets, it's a rare treat; it means that the person selling them probably hiked and picked them up by hand.
When I was little (about 12), I spent about 3 weeks outdoors with my parents, on a prolonged vacation to the mountains. We had some camp cooking equipment so we could make pancakes, and these Clătite cu fragi are one of the things I remember fondly about that trip. They were just there, ripe and ready to be picked up. The best foraging-based snack ever :).
If you manage to get your hands on these somehow, do try these crepes. They're amazing. :)
Last year: nothing.
Two years ago: nothing.
Three years ago: nothing.