I certainly wouldn't want to live in Bangkok on only $550 USD (about 17,500 THB). Outside of Bangkok it could be doable, but it still wouldn't be very fun. I posted my month-to-month Bangkok living expenses a few months ago in this thread:
Cost of living in the Philippines and Southeast Asia
I went into much more detail concerning each expense on that thread, so please check it out before reading what I wrote below. I'll repost those same numbers here, but I'll also include percentages this time. Bear in mind that the below expenses are split between me and my girlfriend. I'm currently working as an English teacher at a prestigious government high school in central Bangkok. I'm usually at my school 25-30 hours per week, Monday through Friday only. I teach only 17 hours per week. I get three to four months fully paid vacation time each year. I occasionally do tutoring on the side to supplement my income, but I won't include that below, because the amount I make from it each month changes frequently.
Net salary (after taxes): 34,250 THB per month
Apartment: 9,500 THB per month (28%)
Electricity: about 2,000 - 3,000 THB per month (
paid by my girlfriend)
Water: 150 - 200 THB per month (
paid by my girlfriend)
Internet: 700 THB per month (
paid by my girlfriend)
Phone line: 107 THB per month (
paid by my girlfriend)
Cable TV: 1,000 THB per month (
paid by my girlfriend)
Mobile phone service (with a 3G package): about 300 THB per month (1%)
Food: about 6,000 - 9,000 THB per month (18 - 26%)
Drinking and nightlife: about 500 - 1,000 THB per month (1 - 3%)
Transportation: about 1,000 - 1,500 THB per month (3 - 4%)
Clothes: about 1,000 - 1,500 THB per month (3 - 4%)
Toiletries: about 500 - 750 THB per month (1 - 2%)
Total expenses: 22,757 - 28,557 THB per month
Total expenses paid by me only:
18,800 -
23,550 THB per month (55 - 69%)
Total expenses paid my girlfriend: 3,960 - 5,010 THB per month
My total salary remaining after paying expenses:
10,700 -
15,450 THB per month (31 - 45%)
Exchange rate as of September 18th, 2013: $1 USD = 31.68 THB.