I understand that you might just look for a low cost product now. With your listed budget and the kind of requirements, we can only expect some quick work probably from part-time freelancers. It may serve well as a demo purpose. However, if you are really serious about software and determined to have a genuine piece which can serve several hundreds OR thousands of users concurrently, having strong codebase and smart UI with high expandability, or you simply need a professional IT team to back and run your app behind your business, please consider hiring Skyscript.