4k installment most likely their debts are around 400-500k...
assuming they buy in their house before 2008 and sell it now..
most likely they can record a nett profit around 400k..
acquire another cheaper property in mainland by paying minimum DP and invest the remaining..
ROI around 12% per annum .. 5 years down the road.. fuhh money grow many times jor....wahahahahah..