Laravel- Create a backend application and provide webservice

Working on an application which will accept user input( via web services) store it in the database send back the output( webservice)

Details
Application will accept around 5 different inputs from the user including pic, text etc via web service, store it in a database and send it back so that other users can view.

Application will also have simple user login using email and password.

basically this web application will be communicating with a mobile app as a reason we might not need any front end effort.
all we are looking for is web services sending info back and forth. hopefully fast enough to handle frequent updates to database

I would like this to be implemented in PHP laravel.

Please provide a rough time and budget estimate.