To the hiring:
Don't ever agree to pay an hourly rate.
Instead, agree on a fixed price for the project. If you pay an hourly rate, and the person you hired can't get it done in time, you'll have to pay more, or at least get into a fight about how much extra it will cost.
With a fixed price, there's no discussion and if the person you hired can't get it done, it's his problem.
To the hired:
$40/h is just about the limit for a job this simple, and it shouldn't take you longer than 24 hours. Thats 960 bucks and that's the top rate for this project.
So far, only kidisgood gave a figure like that, but he doesn't have a profile and doesn't refer to any previous work.
Willet's profile says he doesn't really know PHP yet, so where he gets the $45/h is beyond me.
Aek doesn't have a profile, but the mentioned websites look good (the second one is so-so, but he's working on that apparently) So his requested $40/h seems justified.