The fruit vendor near Phesat Rungroj (there are several, I am talking about the one who sells mangoes). I gave up buying from her, it's just too disgusting.
You said "one" place.
You need more?
Is there a maximum length for posts on AN?
BTW many years ago, the chamber of commerce of Hua Hin discussed, whether to recommend double pricing. There were those who objected.
The result was a quite official recommendation to charge tourists more.
AFAIK things haven't changed in Hua Hin.