tendering website

3 use cases: user ; manufacturer/supplier ; admin user registers on site selects category ; selects product buys that product for free 1.50 charge if there is a pot already created for this product, then num_prods_in_pot +=1 else if there is no pot ; create a new pot num_prods_in_pot = 1 'users 2' receive contact from admin for €x for product a do you want to purchase this product yes or no reply yes or no if yes is >= the number set by the admmin in the tender; then supplier receives contact details for all of the users and the tender is complete ; best tender turns green in ad min section ; pot turns green in admin section supplier registers on site selects multiple categories to be associated with selects multiple counties to be associated with 'suppliers 2' supplier clicks to username / password area to insert price of each product ; lead time for each product, submits see 'admin 2' admin log in [login to view URL] view all products / cagetories ; create new products / cagetories create new categories , products. view all pots set a pot to tender (if product is category = shoes. suppliers registered in this category; then they get notification) pot turns from red to yellow; admin sets a min igure e.g. 5 out 0f 20 products in the pot. this means that if 5 or 20 users say yes, then the tender goes ahead ; if only 2 users want this product at this price... then its less than 5 the tender fails. see 'suppliers 2' 'admin 2' click into pot and view all tenders click into each indiividual tender select the best tender ; this tender turns yellow select contact purchasers see 'users 2' can modify an existing system (drupal ; oscommerce ; ebay clone...) OR create a new system