America could theretically sustain other cheaper losses, like a few more F15s going down - but Trump is rightfully terrified of the political fallout of American pilots being capturred and torture videos showing up on Telegram.
Missiles are always easier to replace then platforms of any kind.
But yes - a single, lone captive could cause political devastation.
Missiles, more expensive - depending on.
Missiles are not 'rocket science' - pun intended. They're expensive because of the overhead of military industrial complex.
Russia is making ballistic missiles 'China style' - super fast, super cheap. Basically - much bigger than ATACMs, longer range, a bit less precise but vicious. Similar to Iran.