You could be on the low end of "comfortable western lifestyle" in the Bay Area for $3k/month, renting at $2200 in the East Bay, spending $300 on groceries and $500 on entertainment. Something doesn't seem right.
So the equivalent of that in Thailand would be about $1300 a month. My estimate of $3k includes a spacious 2 bedroom western style condo with a pool, gym, a nice motorbike, uber, eating out almost every meal, drinking, vacations to the beaches/islands every few months and entertainment.