Dear Sir,
Please let us know how many subscribers will there be?
What are different membership plans for site users? Is it monthly recurring basis or is it per service used?
Which Payment gateway you would like to integrate?
What type of information is user going to input in the website? Does the registered user fill a form or something to input info into the system?
What kind of product or service will be sold? What type of item you are referring to? Is there a relation with the items/service that registered users can choose and the input fields?
There would be email login for the user
Do you have any reference in your mind which is almost similar to your project? It will help us in understanding the basic design requirements you are looking for.
Do you need apps on both the platform i.e. iPhone and Android?
Is this a fresh build or is it a part of an existing system?