If you are thinking to develop a basic IoT app having basic must-have features like device On/Off, Timer, Schedule, OTA update, etc..., it can cost between $40K to $60K. But if you are looking for a feature-rich application with connected hardware, with complex integration like industrial IOT, automation, tracking, sensors, etc...then the cost can go north of $50K. 

If you are a startup and want to create an IoT app with basic features and standard UI then it will take around 12 weeks that includes firmware development, application development and deployment on AWS Cloud. However if the application requires quite many module development, integration and testing, the timeline can vary between 12-16 weeks. 

The maintenance and support requirements for IoT solution development comprise a competent-driven software development environment and a system runtime environment for supporting the modular software construction that is highly secure and robust.

Generally, the process of IoT app development starts by choosing a platform to choose the hardware and development boards, and then you have to think of scalability in advance and then see to it that your app is quick and ready to launch. 

Before taking a call, gather information about their staff’s expertise in multiple technologies, experience in working with different businesses niches, and use cases. Find out what kind of IoT projects they have worked on for their clients. What is their modus operandi like? Are they cost-effective? To get a clearer picture, try speaking to one of their clients and then decide.