We live in a 3 bed house and have a 2.5 year old and a bump on the way. Have just been reviewing our budget in light of this:
International school fees: Starting at 20k+ pa for kindergarten/reception, working up to 30k pa for older kids. Depends on school though, so do check.
Pre-school fees (my 2.5yo attends one of these 4 days a week until she starts
International School) $600-1,500 per month depending on the school and whether full day or half day.
Rent: $6000 pcm (this is very much on the cheaper end of the scale for a landed house as our house is in "original condition" i.e. nothing much changed since 1970. The sky is the limit for prices on landed houses. Most people live in
condos anyway. I'd say aim for a budget of at least 10k per month based on your wife's expectations
Ultimately rental cost is down to location, size, finish and what you're willing to sacrifice. Properties are available in all budget ranges (that is to say expensive, very expensive and holy moly!)
Maid: $900 per month (all in - includes salary, maid tax, insurance, home leave, documentation renewals etc.)
Utilities: $550 pcm - and we watch our bills and don't leave our air con on all the time!
Grocery spend: $2,200 per month - and this is not including fine wines or foie gras!
Travel: public transport is cheap, like $1 per ride. Ideally live close to an MRT station.
Car: hideously expensive to buy and the loan rules have just changed. As you're only here short term, I suggest renting or leasing a car - allow a budget of at least $2k per month.
Taxis: depending on distance and call out costs, e.g. $30 from downtown to airport. Before getting a car we spent $700 a month on taxis.
Everything is expensive here - alcohol: $30+ for a bottle of wine. Hair cut and colour for ladies $300+ Coming from the US you will be shocked at the price of most consumer goods.
I could go on but you get the picture.
On the flip side, income tax here is very low, although as a US citizen I guess you still get stung by Uncle Sam.