Bottle of Lao Kao 60 bt at the village store/bar, bottle of smokes or 1g of weed 70 bt, some fresh veg and chicken/pork for 3 stir fried wok meals at home and you've eaten well the whole day, got drunk and high for about 200 bt.
Hel, splurge and go HiSo with a bottle of Saengsom and you might hit a whopping 400 bt.
Do that every day and you're at 12,000 bt for the month. Rent a decent aircon room or small house for 4-8,000 and you're at 20k max.
Add another 10k for some incidentals/treats/misc. and you can live comfortable in a 24/7 haze for US$1k or less.
It's still possible. For losers. But that's how most expats come across anyway.