Every-time I decide to go on Keto Diet, I can only sustain for about 3 months. It's not sustainable in the long run as well, we are in Malaysia after all.

Cheapest way is still to cook your own meal. and IMHO, this diet can get pretty expensive. During my 3 months keto diet, I mostly eat eggs, butter, almonds, beef bacon, peanuts, vege. same shit everyday. low carb, low protein, high fat.