Ask News.YC: Pricing Social Network Site Built Costs

If one wanted to have a 10k-60k userbase capable social network built from scratch (video, music, comments for media (not for members), groups but not "friends and friends of friends", internal message client simpler than gmail/yahoo mail, calendar, with private and public permissions set by users), blogs, individual user file archive with permissions.

what might something like that cost if built pretty much from ground up?

thank you in advance for your input for all those that know, might know, and care to share.