Hello! I have read your requirements carefully and I want to tell you that I have 6 years + experience in the area of your interest.
1) To develop a very advanced and mature PHP website.
2) Perform a technical analysis of requirements.
3) Produce a solid, detailed technical design and documented software.
4) To write clean, modular, robust code to implement the desired requirements with supervision.
5) Customer/supplier verification, customer/supplier review.
6) Management Application installed on owner's computer, which can prepare products, offers before adding to website without internet access, so that process of preparing and describing offers or product is independent from internet access
7) It should ensure uninterrupted application , also in a situation where you have problems with internet access , so if there is no internet access, it will be possible to connect to the Central Database
I will keep all these things in mind as well as many more things. I will give you the best value for your money. If you can initiate a chat, then I am ready to negotiate about the price also, as I just gave a rough idea when I was trying to bid for your project.
Thank You for your valuable time, I will be looking forward for your reply !