I would not complain if the quality is good - but these are microwave-heated food. The shops seem to be capitalizing on the fact that passengers have no choice. Compare NAIA with other airports - Bangkok airport have fastfood joints or sit-down type restos, so does Singapore, or Narita, or Schipol, or Hongkong .... the list is long actually. These airports have McDonalds, Burger King, and other fastfood joints with the same prices, or maybe just a little bit higher than their stores outside the airport (but definitely not twice the amount, like the "golden" siopaos at NAIA). If you want to eat a fancier dish and willing to pay more, there are choices in these airports.
Now going back to NAIA's siopao and mami... I really wonder what's so special about those siopao and mami. Maybe they taste good... but, despite my hunger, I can't make myself buy those food and patronize the food shops - it's a matter of principle!! I may pay P100.oo for the cup noodle at a Cebu Pacific flight- at least the stewardess can justify the price; "Hey, isn't it cool, you're eating cup noodles on air!".
(NAIA, as we all know, is named after the modern-day hero, Ninoy Aquino. He probably would turn in his grave if he learns about the pitiful state of his namesake.)