The first bit should look like this:
Code:
Object = Nuke_ChinaAirfield
CommandSet = Nuke_ChinaAirfieldCommandSet2
ReplaceModule ModuleTag_25
Behavior = CommandSetUpgrade ModuleTag_25_Override
CommandSet = Nuke_ChinaAirfieldCommandSetUpgrade2
TriggeredBy = Upgrade_ChinaMines
End
End
Your price and build times code is right, but it will only work for objects that already have those lines in their code, not for objects that do not have them (eg cvilian things).