I for one do not agree that "taxes, etc." should amount to more than the basic amount.
The other day, I requested air fares for DXB-KHI on various carriers. EK had (not surprisingly) the most expensive fare, but to my astonishment, QR offered the lowest at only Dhs 450. However, they also levied the highest "taxes" (or whatever goes under that heading in UAE) at a whopping Dhs 540
, making them the most expensive choice.
Clearly, nobody in their right mind would expect or accept the tax component to be higher than the principal amount.