This is something I've wanted for years. I wish I knew the price though. There is a tendency to overshoot on the price initially and the result is turning off most of the potential market.
Does the purchase price include user rights comparable to other digital content, like ebooks? E.g. can the article be downloaded for offline reading or searching?
I'm not sure about the specific legalities (I'm a developer at Blendle) but our iOS client offers offline support and we integrate with services like Pocket.