The honest answer is: it depends on what you are building. But 'it depends' is not useful when you are planning a budget, so here is how we break it down for clients.
Platforms. A single cross-platform app built with Flutter or React Native costs much less than two separate native apps, and for most business apps the user experience is just as good.
Features. Login, payments, chat, maps and admin dashboards each add real development and testing time. Listing your must-have features for the first version is the single best way to control cost.
Design. A clean, standard interface is faster to build than a fully custom design with rich animations. Both are valid — it depends on your brand and audience.
Support. Budget for hosting, monitoring and updates after launch. A product that is not maintained slowly breaks as operating systems and libraries change.
Our advice: start with a focused MVP, launch it to real users, and let their feedback decide what to build next. Try our cost estimator for a quick range.