I'm not afraid to admit that I make a mediocre salary in Bangkok, Thailand. Just my core salary (full-time job salary only) is right at 35,000 baht per month. However, money is definitely not everything when considering a job. I love my job, and I have tons and tons of free time and vacation time. That also means I have plenty of time to make extra income on the side (though I seldom choose to do so). The OP is wanting to know specifically how much one pays for regular expenses month by month, so I won't go into the details of my job, other than by saying I'm an English teacher.
I should note that I split my monthly expenses with my girlfriend, so I don't pay 100% for everything. Approximate monthly expenses for me in Bangkok:
: 9500 baht per month. I live in a semi-spacious studio with one bathroom. My apartment is right smack in the heart of Bangkok, within walking distance to a major park, the BTS skytrain, and the MRT subway system. There's tons and tons of entertainment (such as the Patpong night market) and food surrounding my apartment in every direction. I just moved out of a one-bedroom, one-bathroom apartment that was 9800 baht per month. It's only about a half a mile from my new apartment. I moved because I wanted to be closer to my workplace.
: usually around 2,000 baht per month. I run the A/C and a fan whenever I'm home, I have an LED TV with cable TV running regularly, and I have a few computers running semi-regularly. Other than that, I don't do much electricity-wise. I pay 5 baht per unit, so I suppose I use about 400 units of electricity each month.
: usually between 150-200 baht per month. All I can say is both my girlfriend and I take a shower once daily, and we wash our hands regularly. We also occasionally wash dishes whenever we have cooked at home.
: about 700 baht per month. I have a 10 Mbps DSL connection. It's direct from the internet company (not shared wi-fi).
: 1000 baht per month. I have HD cable with all kinds of channels. I usually watch the American ones, like National Geographic, the Discovery Channel, and HBO. There's too many other channels to mention, but I should also note there's a few Chinese, Japanese, Korean, and of course Thai TV channels on my package.
: I would guess on average I pay anywhere from 6000-9000 baht per month. Food expenses are really hard to measure, because I eat all different kinds of food and at all different kinds of restaurants. When I eat Thai street food, I usually pay 30-60 baht per meal. The meals usually consist of rice, noodles, vegetables, and a little meat. Same goes for when I eat at a Thai food court, but then I usually pay 50-100 baht per meal. I sometimes eat at nicer restaurants, which usually average 200-300 baht per meal for one person. I frequently eat fruit from street vendors. It's usually anywhere from 10-25 baht for a small bag of tropical fruit. I also buy a lot of healthy snacks at 7-Eleven and the supermarket. I usually buy sugar-free tea, fat-free yogurt, dried fruit, and nuts whenever I go. One day of snacks is probably around 100-150 baht. When I buy food to cook at home, I usually pay about 500-750 baht per visit. My shopping cart is usually filled with chicken breasts/thighs, fish, vegetables, fruit, nuts, black rice, and fat-free yogurt. This is usually enough food to make one meal a day at home for one week. All in all I think I eat extremely well, I'm rarely if ever hungry, and I feel quite satisfied with my meals. I practically never have "eater's regret" (the feeling you get after you've just finished eating something you know is detrimental to your health).
Drinking and nightlife
: I might have one or two late nights out with friends per month. Each time I go out with them, I usually spend 500-1000 baht. Usually I personally consume a handful of local beers, eat at a nice restaurant, take a taxi or two, and go into a bar or two. I'm not a big drinker, so bear that in mind. Nonetheless, I do usually have a pretty good time when I go out with my friends. A few words of warning: alcohol and nightlife are definitely not bargains in Bangkok.
: I would guess around 1000-1500 baht per month. 90% of my traveling from point A to point B is done via the BTS, MRT, or via a bus. I rarely take taxis. I usually only take them when it's super late, and there's no other options. Bear in mind that the BTS, MRT, and some buses stop running at midnight, so after that point, taxis are your only real option. I should also mention I do A LOT of walking. I love walking, so this doesn't bother me one bit.
: also around 1000-1500 baht per month. I might buy a couple of new shirts, a new pair of pants, a cheap pair of shoes, and/or some other random clothing items each month. If you haven't heard already, Thais strongly judge people based on their appearance. I naturally like maintaining my appearance, but I do admit I try harder now that I'm living in Bangkok. I buy most of my clothes at a placed called Export Shop, which sells clothes that were rejected by retailers for whatever reason. Usually it's just some tiny unnoticeable flaw, but sometimes it might be because of discoloration or a small hole. If you look hard enough, you can find some nice quality name-brands, like Dockers or Levi's. There's definitely some great bargains to be had at Export Shop.
: maybe 500-750 baht each month. This includes items like shampoo, conditioner, soap, toilet paper, face wash, toothpaste, etc. When one item runs out, I replace it with a new one. I usually by decent name-brand items, like Gillette and Nivea. Other than that, not much to say about this category.
Overall, I think my financial situation in Bangkok is quite good, regardless of my mediocre salary. Living with another person who can split the bills with you definitely helps significantly. I can usually save between 6000-9000 baht each month. I usually travel internationally twice a year (such as to Laos
earlier this year) and also travel domestically within Thailand twice a year. I do occasionally buy something for myself, like a new hard drive or mobile phone. I have to watch my money somewhat carefully, but I don't have to count my satang (Thai pennies) either. I'm sure I've probably accidentally left some expenses off of this list, but even if so, they would be small expenses that don't add up to much.
Life at the moment is pretty good for me: my job is low-stress and somewhat rewarding, I have tons of time off, I eat like a king, I travel regularly, I constantly have a new supply of clothes, and I have late nights out with friends a few times each month. And of course I'm living in an interesting foreign country, which makes life so much more interesting than living back in home in the United States. When it's all said and done, Bangkok can be as cheap or as expensive as you want it to be. You can live like a peasant or live like a high-roller. There's definitely a lot of temptation to spend here, so you have to have a lot of self-control. I encourage anyone out there who's considering to live in Asia to just hurry up and take the plunge. Even if you fail and move back home with your tail between your legs a year later, I can promise you that one year you had in Asia will be an unforgettable year of life.