Dear Sir,
I have gone through your project details carefully and as far as I understood, either it would be a re-seller store or an auction site with ecommerce features. It will also have multiple payment processing options other than Paypal too. it will also the social media integration for sharing purpose and likes as well.
Moreover, you want the email sending option with an email Template for news letters or any updates to the users by your admin site. We have complete range or required skills and very much comfortable to get started after discussion and defining the exact scope of your project. Bid is tentative and subject to change after.
I'm flexible to discuss further and looking forward to hearing from you soon.
Thanks,
Ahmed T