Yeah, this is true. PS2 was more expensive, and it was sold at a loss for a long time.
PS4 is already profitable. Sony did all perfect this Gen, releasing the most powerful Console VS MS and Nintendo, at a very competitive price, a very balanced and friendly to develop for piece of hardware, finally !
Every developer is so happy with PS4, which is mostly the lead platform for multiplatform games.
Congrats Sony ! Right now should be around 10.5M units sold after only 9 months and half from Launch.