Major screw-ups? Stupid things you did when you were drunk that lost you money, legal problems with a local, real-estate fuck-ups, an expensive relationship etc.
Not putting a buttload of cash, which I had, in the stock market after the financial crash in the late '90s. grrr
[color=green]Making a visa run during SARS.[/color]
getting paid in USD.
Not putting my savings into Euros when the rate was much better.
Moving back to Australia
Getting a Taiwanese girlfriend. 
Not buying a house in the late 80’s
Buying a house in the mid 90’s
Leaving for graduate school.
Not having met my wife earlier 
“Most expensive mistake” isn’t that a Sheryl Crow song?
Mine is not having enough money to be able to make expensive mistakes.
Madame Olga at the “Happy Time KTV”
Allowing the siren call of the xiaojies to lure me away from my lucrative career in London.
:bravo:
Come on, nobody’s going to admit to marrying/having as a girlfriend a local, starting a business (like a cram school or pub or restaurant or club) which you mostly run but is technically majority owned in her name because you are the foreigner and can’t legally own majority share in a business, and then when you two break up, she takes most of the pie. I’ve heard that happening to plenty of foreigners in Taiwan. Some of y’all are probably on this board. 'Fess up.
I’ve made many, many, many mistakes in my life.
By far the worst since living in Taiwan was to get a dose of the clap which got into my prostate gland and caused me more misery than God ever dished up in the first testament. (Cautionary tale for the rest of you)
From this I recovered only to crash my motorbike in a drunken stupor and fuck up my left knee. This is an injury I carry with little pride.
There’s more much more, but what’s the point of making you guys feel better at my expense.
My only expensive mistake so far would be me leaving my very lucrative career back home in the states for my very lovely xiaojie here. (I guess now it would be Tai Tai), BUT I am very satisfied with my expensive mistake.
I will agree with Richard M. Not enough cash to make an expensive mistake here.
Working at a job I loved. God, they certainly have no compunctions about using people here.
Going home after the first 180 (has to be 183) days for Christmas. Come March, those three days cost me about 45 grand.
Rubicon - foreigners can own 100% of a business and have it their own name. Your info is quite old.