I need to create an online classifieds marketplace to sell car parts for buyers and an android app for sellers. I need to add an option where buyers can make a request for a specific car part and buyers in the related category receive a notification on the app and can make an offer. All the contact between the buyer and seller should be only through actions without the buyer knowing any information about the seller. The website should include payments and delivery options as well. Please bid only the budget you're ready to work with to avoid wasting any of our time.