Build A Website/Platform Similar to The one mentioned in the Description

Hey Freelancers! We need an e-learning platform similar to [login to view URL], [login to view URL], [login to view URL], etc. The platform will include, live video streaming too. We basically need a platform on which students can register, and purchase different learning modules(Fixed.). And, the instructor can teach the module. The teaching will happen by Displaying of Slides and the instructor elaborating them(Audio support). The instructor should also be able to conduct tests(MCQ's), share notes, send messages, etc. Further intricate requirements and details can be shared upon agreement. I want the following details:- 1) The approximate time-frame required by the developer in developing such a platform. 2) The charges by the developer. 3) How you'll manage the front end and back end( I don't have much knowledge so please explain it to me if possible). 4) The approximate costs involved in the upkeep of such a platform? Hosting Charges, maintenance charges, etc etc on a monthly basis. 5) Please share if you have worked on a similar thing before. Looking forward to a fruitful association. Thanks and regards! MockDTAW Team