Oh, and the client only wants to spend $1500.
What software are you going to use?
Many PHP projects are driven by momentum. PHP is a language to get things done in, and I know plenty of incredible PHP programmers who use PHP because it has unparalleled adoption and a library of off-the-shelf OSS software that can't be rivaled by any other programming language.
I'm pretty okay with people shitting on PHP, but shitting on PHP programmers is a completely different story. We use PHP because it gives us a leg up that no other programming language currently can.
Unless you've only been a programmer for a few years, you'll understand the libraries matter more than the language when it comes to writing software. In that regard, and with regards to the OSS software written in PHP, it probably comes close to or beats CPAN.