Hi there,
I could build a client area with user registration, login/out, profile to edit, image upload, and admin access to manage the users for $300 in about 10 days (give or take a few based on your changes and requirements).
If you provide me with more information and details on the project I could give a better quote.
I have been coding in PHP since 2007. I'm also highly proficient in the CakePHP web framework in which I've built a few social networking applications and have done some consulting.
Thanks,
Andrew