Seafood With The Local Thais

Tourists are always overcharged in developing and underdeveloped countries for many items. This is the way it is, probably the way it always has been, and there is really nothing you as a tourist can do about it. Blatantly, the admission to the Emerald Buddha in Thailand has two separate prices: one for Thais and a more expensive one for foreigners. I refused to go.
Sometimes, off the beaten track, you'll get what to you seem like ridiculously low prices in out of the way countries. But you're still being overcharged! That is nothing to be indignant of course, but rather to be thankful that tourism hasn't invaded yet.
In Koh Samui, Thailand, there is (or at least there was) an out of the way seafood restaurant set on the top of a cliff with gorgeous views. No farang (foreigners) knew about it and only well off locals and mainland guests dined there.
I had spent enough time in Koh Samui by then (1990) to have made some connections. One was an older gentleman who only dressed in sarong and owned a coconut plantation as well as a cheap bungalow. Between his hundred words of English and my twenty words of Thai we somehow managed to communicate on many topics.
One day he told me about the seafood restaurant and we went that night. We also gave him a bottle of scotch that we had bought at the duty free shop and that he graciously served to all the guests (mostly his family) during the meal. The restaurant had huge tanks full of every name of fish, shellfish, and crustacean. I pointed randomly at anything and everything. Plates began arriving at the table and every single morsel was sumptuous and perfectly seasoned. We ate and ate.
Amazingly, the bill was $50 U.S.! That was the local price.