consumer/contractor website (reverse auction style)

I am in need of a website. The site is essentially a reverse auction type style. An example of how the site should work: A consumer is searching for a specific service such as an electrician to wire their new house. The consumer would register on my site, fill out a brief description of the project/service they require, and post it into our database. The electrician would register on our site as a contractor, pay the monthly fee, and receive access to all posts in his designated area and that relate to his trade/service. The contractor would then receive access to the posts and be capable of contacting the consumer to coordinate a bid or service. The site must feature several databases for each trade/service, accessible only by individuals who receive permission (contractors who paid). Filters so that contractors can only view posts in their assigned region. Must feature forms for both the consumer and contractor when registering for the site, must have custom forms for consumers to post their project or needed service, some sort of eCommerce system so contractors can pay monthly membership fees. The site is nearly 100% automated. But I want administrative access to most if not all. I must be able to receive the site upon its completion and be capable of running it with in house IT personnel. International developers are welcome to bid, but you must be capable of speaking and understanding english fluently. Look forward to the bids and messages. I have received bids in the past from a wide range, and I have spoken with several developers in regards to this site. I know what the appropriate cost would be. I have established a wide pricing range to weed out developers who are over pricing me. Please post what you believe is fair. Site designers with related work in their portfolio will receive special interest, especially if their price is within range. Thank you for reading.