Creating a website takes a bit more than what you may think. However, I will accept less payment depending on how much work this actually takes. I assume, that since you are requiring PHP, that this site will have some form of a register/ login system for users.
Which, means of course, that it costs more than creating the HTML & CSS of the site. I understand I have no proof that I even know PHP or HTML, but check out my profile page and go to the Portfolio and you'll see that I know everything there is to know about creating a register/ login system in PHP.
Plus, I won't charge tons of cash.