What do you mean baggage fees? All airlines listed here allow free baggage allowance of at least 20kg (30kg for MH), with the exception of Air Asia.
How much luggage do you have? Excess is usually calculated based on the full fare of the route. Each airline is different except MH which has a zone system, and Air Asia. Check each airlines' website. For ST, has it occurred to you to ask on the ST forum?