[burriko]

'custom search feature, social networking/profile features'. These terms are so broad in their scope that it's really not possible for anyone here to estimate with any accuracy the time/cost it would take to implement them.

If you actually do have a detailed spec then I'd recommend that you simply approach a web dev shop/freelancer and see what they say. Explaining the details of what you require is the only way that you're going to get an accurate answer. You may even want to tell them what your budget is up front so that they can be realistic and let you know what's possible for that money. We've all dealt with clients that have very tight budgets, so it's certainly not an unusual request.