Well, the reliability of the article may be questionable, the last paragraph says "The defence minister said in October that Taiwan had spent almost $900 million so far in 2020 on scrambling its air force against Chinese incursions". $900 millions seems like an awful lot for fuel... Or am I missing something?
This is not just fuel we are talking about here. Keeping a fighter aircraft in operational conditions and sending them on emergency intercepts are very taxing on the airframe. If anything the real cost is understated.