Hi,
Many thanks for taking the time to explain a little bit about a social networking site; I am on a bit of a role at the moment with these type of sites and have got my first feed back on freelancer as a result of this type of site too =))
The type of site you are looking for I would build for you using Joomla as the Foundation Platform and a Community Extension module called Joomsocial; the cost of such a site at the moment all in based on the number of hours required is $1,800 and about a months worth of work.
I am prepared to reduce my rate, to get another community site on my bow and to get the feedback on freelancer.com; the minimum I can get it down to is $1,000.
I have enough experience with this to help point you in the right direction and can show you how we can link this to the likes of facebook to get the traffic you need to make this a success.
I will also send you my portfolio by PM for your perusal.
I look forward to hearing from you soon.
Kind regards,
Darren