MH promotes adding on a Malaysia side trip if you are transiting through KUL. They say you only pay the extra taxes:

https://www.malaysiaairlines.com/au/...side-trip.html

However, when I book a trip and add the bonus side trip, the difference in the total price is much more than just the additional taxes. In fact, it's the same price as if I book the same itinerary using "multi-city".

For example in Economy SYD to SGN is $AUD 952 in total. If I add on Langkawi it comes to $1352. This is for March 2026.

Is the Bonus Side Trip really not free and a bit scammy?