When you have an idea for an App don’t approach someone to develop it straight away. You need to do your research and understand where it sits in the market, be clear on the value it will provide and price it accordingly.
Just picking a price because competitors are doing it doesn’t mean anything. You really need to consider continual updates, upgrades, maintenance, support and hosting to ensure you can have a successful business.
Be clear on the value your app provides otherwise people won’t use it.