I can only ever afford to eat oysters at eat-all-you-can buffets where you pay a certain amount of entrance fee and then stuff your face with food.
The first time was in 2010 at Nikko Hotel KL where they had Japanese buffets every evening. I don't know how much it was because I wasn't the one paying.
I took quite a lot of oysters not because the taste was particularly nice, but because I knew it was expensive, and very French, therefore fashionable. Haha.
2015: I renewed the experience at Mitasu restaurant KL, where I finally got it on camera.