Before I can provide you with a meaningful quote, I need to know more about what you need the application to do.
I'm happy to work with you to better understand your requirements but at the moment, your request could cover anything from "Hello World" which I assume would be of little benefit to you, through to a fully functional e-commerce system that would take months to develop.
Please clarify what it is you hope to achieve so that we can discuss further. Feel free to message me through the site.