The primary cost differences I have experienced come with maintenance and fees, not the initial build.
Maintenance = iOS version updates, dependency upgrades, App Store requirement changes, etc. have been costlier and more out of your control than with web apps. Fees = the App Store's 15-30% fee is more expensive than using a web payment processor.
Maintenance = iOS version updates, dependency upgrades, App Store requirement changes, etc. have been costlier and more out of your control than with web apps. Fees = the App Store's 15-30% fee is more expensive than using a web payment processor.