Build a website project

I'm looking to build a website where I can sell some pre-loved items (clothes, accessories, shoes etc) It must be a very secure website with different types of payments and users. I'd like beautiful responsive design. I require a diligent freelancer/ team and I\'m ready to pay for the services. Interested freelancers should answer the following: 1) What are your skills? Send your portfolio. 2) What platform/ programming language will work best for such platform? I was thinking about WordPress because I've had positive experience using it. But I\'m open to suggestions. 3) Have you built similar website? 4) What approach do you use? What is the best approach for my project? 5) How long the work might take?\ 6) How much the WHOLE project will cost? I need a ballpark obviously. 7) What can you advise me about design?