[johncalvinyoung]

Their business model for a long time has theorized that they can deliver an operating cost that would allow airlines to offer tickets at roughly current business class ticket costs, which would be a fraction of Concorde ticket prices expressed in current dollars.

I don't know if those theorized efficiencies will be delivered (a lot depends on that engine) or if airlines will price tickets at that level. But it's the theory so far.