Build me a Buy and sell website

I need a website where people can post and sell quick items or start their own small business profile and sell items on their profile. I have a Facebook group with almost 20,000 members. I want to make something where people can post their quick items and then they get deleted once sold, you know what I mean? Then I also want small business profiles that I can approve. I would also want to be able to post exclusive announcement where they get posted in the top of the website when I need to post something. Thank you!