Budget E-Commerce Mobile App

I’m looking for a lean, no-frills e-commerce application that runs smoothly on both iOS and Android while keeping the total build cost below $30. The core aim is to let customers browse items, add them to a cart, and check out through a simple, intuitive interface... (Budget: $10 - $30 USD, Jobs: Android, App Design, iOS Development, iPhone, Mobile App Development, Payment Gateway Integration, PhoneGap, React Native)