While I doubt it's true anymore, I'm sure at launch any profit Sony was making on hardware itself was probably razer thin. For all players involved (Sony & retail) selling the consoles themselves isn't nearly as profitable or important as the software and subscriptions, which is probably one of the main reasons Sony made PS+ mandatory for multiplayer. If they can assume >50% of PS4 buyers will add an extra $50-$60 to their purchase, especially on something Sony doesn't have to manufacture, well then there goes any question of PS4's profitability. Throw in a couple game sales and each PS4 is a healthy, profit-making machine.
So it's not out of the realm of possibility for Sony to be making very little on each PS4 sold, it doesn't matter all that much. Though I agree nowadays thanks to cheaper parts and a cheaper slim model, they probably don't spend as much on hardware as they used to.
