App.net is no longer $50/yr. You can choose to pay monthly at $5 or for the year at $36.
Is this a response to Tent.is coming out for free with a $12 a month plan for “early adopter” status? I don’t know. But either way, if the way forward is going to be a paid social networking solution (and I’m all for that) I’m glad to see some competition in this space.