This contract would require everything online built from scratch to interface with an offline filemaker db via exports and imports. There needs to be a couple of levels of security.
I'm not quite sure what you are aiming for. Are going to build a website from scratch using PHP?
I'm no professional, but all the theory I've been thought, is that you don't give a client hourly rates!!!
You need to talk to you client and find out what they really wants. Write down a System Requirement Specification (SRS) and go through that. Find out the functionall and non-functionall requirements, find out how difficult it would be to design / implement them, then calculate how long it will take you to create it. The ngive them a proposal for the whole project.
I don't know how u do it in the states, but here on the other side, we do it a bit differently :-)
Good luck.