Thailand is an amazing country. The people are open and friendly from such a deep place that it's hard for a cynical westerner to grasp. The food is great. So are the arts and culture. It's really hard to go wrong with Thailand. But, it's not undiscovered. You'll see a lot of foreigners around. The country is heavily traveled, though I suppose that makes it easier.
(Rated from 1 to 3; with 3 being best)
Affordability: 2.5 - 3 (Bangkok is expensive, but once you go outside the capital things get increasingly affordable.)
Hassle: 2 (1 for visa, 3 or less for housing, 2 for everything else.)
Affordability:
Housing in Bangkok is not that cheap. It's probably cheap by western standards, but that's not affordable enough for me. Outside Bangkok housing is more affordable. I stayed at a nice clean hostel in Chiang Mai for US $3 per night.
Food is very cheap. If you have a kitchen you can buy food in the store or at the market that might be half or less the price of what it would be in the US. Eating out is also cheap as long as you eat at the right places: the good ones. You can get a small, but reasonably sized portion of food for US $1-2.
Transportation doesn't seem like a huge bargain to me, but it's not expensive either. A ride on a Bangkok city bus cost US $.50, the subway was priced according to distance traveled so US $.65 - $6, a first class sleeper train from Bangkok to Chiang Mai during busy season was US $40, a songtaew (truck taxi) around Chiang Mai was about US $.50.
I don't know first hand about medical prices, but I've heard prices are low.
You can get a Thai (non-freaky) massage for less than US $6 per hour in Chiang Mai. A bit more than that in Bangkok.
SIM card rates were cheap too.
ATMs charge foreign cards a high fee, though if you have the right card it will get reimbursed anyway. Some fees were about US $5 per withdrawal.
Hassle:
Visas are where Thailand falls short. It's a hassle. If you fly into the country you can stay for 30 days without a visa. If you enter by land or sea you can only stay for 15 days without a visa. There's a limit on how much time you can spend in Thailand per year without a visa, so you can't just fly in and out each month. You can go to an embassy outside Thailand and apply for a tourist visa which costs money and allows you to stay in Thailand for 60 days. Either way, you'll be spending time and money working out the visa situation.
Housing is less of a hassle than in Malaysia for a couple reasons. First, there are plenty of one room/studio apartments for rent. Second, short term leases are more common. However, many places that will accept a short term lease still expect a three month lease, which you will note is 30 days longer than a tourist visa. Overall, you can work around the system and expect to find much less hassle than in Malaysia finding housing.
Plenty of reliable banks and ATMs around.
I had a horrible time trying to find vegetarian food in Bangkok. In Chiang Mai, I couldn't turn my head without seeing a vegetarian menu sign.
I found English speakers in the remotest of places. The friendliness of Thais makes communication easy to deal with anyway. Thai is a bit hard to learn, but not impossible.
Conclusion:
I really like Thailand. It's a vibrant and interesting place. If the visa situation were easier I would name it a top ERE country.
