It has nothing to do with the amount of money. If you stay more than 180 days per year in most countries around the world, you must file taxes in that country. Taxes paid are based on worldwide income, and the agreement that the country you are residing in and your home country have together. Good luck.
My husband and I are at Fever Muay Thai in Chiang Mai
Currently, they offer a six month group class, one time a week
We however, signed up for twice a week, private classes, and have paid more money. They are marvellous and very accommodating to our needs as we are both older.