18% Massive ? U.K. prices (and in Europe) are scheduled to TRIPLE and from a higher base, meaning average of circa £5000 per year for average house next year ! Add in that diesel is approximately 75 baht litre and I have to say the costs savings being in Thailand have increased considerably.
That is not to overlook the fundamentals of Thai people being generally much poorer and the difficulties in absorbing increases being onerous. But this is part of a wider problem related to inequality and corruption which isn’t going to be solved soon ,so the short term answer is to subsidise those essentials to affordable levels.