"senior Royal Thai Army (RTA) officer (74 years old ??????) shot dead a junior officer (69 years old ????) whom he suspected of stealing belongings from his residence in the central province of Lob Buri.
Less than 150K, so say 125 per term is 250K per kid = 500 K for 2 per year. Don't think that is affordable on a 80K salary as it is more than half his salary per year.
Your extension of stay based on working ends the day you stop working. It might be that the school meant to say that they will inform immigration by the end of the month with a delayed date for not working