Create a PHP MySQL version of my static php website

5 years ago I built what is now a fairly succesful online directory.
The trouble is, I built the website manually, page by page using Dreamweaver, and now I would really like an online directory that is dynamic, uses a database and it much more automated, rather then my current system of receiving new listing details via a web form, and having to manually update each page in Dreamweaver by copying and pasting the info I recieved via the online forms.

Even the contact forms, and new submission forms were added by me using a Flash form builder as I simply didn't have the HTML knowledge 5 years ago, and I hadn't discovered CMS like Wordpress.

Basically, I am looking for my current site to be replicated, but when a visitor adds a new listing to the directory it automatically updates (after an admin approval, and PayPal payment).
I have seen and used DirectoryPress which is a Wordpress directory theme, and is pretty brilliant, but I want my site to look the same as it is now (or better), and not use an "out of the box" solution that makes my site look the same as all the others.
There are 3 different listings for advertisers to choose from, all of which have a different cost and a different look and place on the website.

I have no idea what people would quote for such a job, so please feel free to contact me for more details of the project.