Custom WordPress Theme with Contributor Section Needed

I have a website concept in PSD format that I would like converted into a WordPress theme. There are several requirements: 1) There needs to be the ability for visitors to sign in and contribute blog-formatted content. Ideally, this will consist of a form allowing for the uploading of editorial content, images, and requires the approval of an administrator. 2) The homepage will derive its content from 5 category pages. 3) The nav bar will be jQuery, but I will provide the pre-made elements, so no Jquery work is actually needed. In essence, this site will be content driven, like a blog, but with the contributor section. I have been quoted between $400 and $450 by several PSD to WordPress sites, but my budget is much less. In my opinion, this is not a very labor intensive project, but it is just beyond my realm of expertise. I will provide more information upon receipt of qualifying bids. Thank you