If you are coming to Thailand, the very first thing you should do before coming is to PLAN out your holiday for YOUR BUDGET!
There is no sense asking strangers on Facebook or Social Media, what is the best place, if they do not know your budget.
Their budget may be much higher or lower than your own.
You need to understand exactly what your holiday experience will be for your budget.
State your budget, before asking questions.
Hopefully, you will be able to plan a list of places to stay and things to see and do in your allotted budget and there will be no unpleasant surprises.