Just out of curiosity, I have two questions:
- Is it really worth paying for business class on 4 hour flight (SIN-HKG) at all?
- Is it really so significantly cheaper to do what you are proposing, considering that it will mean that you will spend close to 4 hours extra flying each way, plus connection times?
To be honest, I simply cannot see why I would fly for 1:50 (SIN-CGK) spend another time waiting, then another 1:45 going back to SIN and then another 4 hours to HKG, if I could do simple SIN-HKG in four hours. Basically simple 4 hour flight becomes nearly 8 hours of flying (plus about 3 hours of layovers) with all the added risks of missed connections etc...
Well, unless it is a mileage run... Then you're talking about luggage, so it does not seem to be the case.