Samui is a iland for vacations and therefore the prices are very high (most 3 or 4 times higher for food than elsewhere).
But if you move a little bit out of the tourists center, you find a lot Thai Restaurants with Thaifood that`s a lot cheaper than in the restaurants for Tourists, also the taste is much better.
You get it ? Cheaper and better Food ? – Yes, but therefore the ambiente is a little bit different 😉
I like those restaurants a lot – but be careful – do not forget to say “not to spicy” – otherwise you will burn a little..
On the main Road , there are a lot of those restaurants.
Look the prices yourself (Photos)