I take you Grocery shopping with me at Big C Extra in Pattaya, Thailand to figure out my monthly grocery bill. This video will give you an idea about how much it'll cost you to eat for one month in Pattaya, Thailand if you only eat groceries and don't eat restaurant food for a month.
I eat healthily so shopping in Thailand compared to the US has been a pleasant surprise. The food I buy is 1/3 the cost of what I pay in the US. To live and eat healthy in the US is expensive. In Thailand, it is very affordable. So if you're planning a long stay or moving here, it's a great opportunity to make a lifestyle change and start eating healthy if you haven't already.
Pork and especially chicken are the best deal if you're a meat-eater. The beef is terrible unless it's imported from Australia and that of course is expensive. The fish in Thailand is ok but not great. Vietnam is a much better place to be a fish eater. I eat fish almost every day in the US but here in Thailand fish doesn't seem to be their specialty. Stick with Pork and Chicken, especially at restaurants. I've had good fish but it's been a rarity.
I think it's worth a person's time to learn how to cook Thai food so you can enjoy eating at home without relying on restaurants. Thai food is simple, delicious, and usually quick to prepare.