<span style="font-size: 10pt; font-family: Arial;" data-sheets-root="1">We are preparing a budget for a new Android shopping application, but different developers have provided very different estimates. I&rsquo;m trying to understand what actually drives the price before comparing proposals. How much can factors such as the number of screens, integrations, authentication, payment functionality, backend work, design, testing, maintenance, and post-launch support affect the overall development budget for an ecommerce Android app?</span>