Build backend using PHP / MySQL / CSS / JS for our existing website

We have a website and take orders from customers. All information is stored in a MySQL database. We need to allow our customers to login using their email and password (which is already stored in our database). Once signed in, they will be allowed to make changes to the existing information like change shipping information, change billing information, change plan, delivery dates, frequency of deliveries, etc. Once all information is entered by user, we need to update the db, and call a function that will take the new information and submit it back to infusionsoft using an API (we have the API code for the most part). There will be a total of 10 pages to be designed. We use bootstrap css and js, so most UI changes will be using a similar style to what we have. We have a common header and footer file that is being included on the site. So it will not be a very design intensive project, but the forms, submissions, API calls, need to be taken care of. We are outsourcing this project because we have a very short deadline and our inhouse developers will not be able to complete this in the next 2 days. WE NEED someone who can start immediately and get these pages done in the next 2 days. We will send you name of page to be designed, fields in the db that need to be updated for that page, etc. I am a developer myself, so will make it easy for you to understand what needs to be done. Please get back to me ASAP with an average cost for the above work. If we need more work, we will gladly pay extra.