I had to live without an AC for a few months, due to some renovation hiccups. Surprisingly, it’s not a big deal even in Phuket climate. A simple fan and plenty of ventilation can make it comfortable to stay inside a house even when your thermometer shows +35°. A typical fan draws about 50 W at full speed, so you can run it 24/7 and burn just 36 kW⋅h a month, which is about $5, according to local tariff.
I ordered the most power-efficient AC units on the market (SEER ~26, COP ~5), and they should be installed in a few days, but I doubt they will even come close to what a simple fan can provide in terms of price to value.