People "Think" they're getting a good deal.. but in mass production, most of these components are pennies on the dollar you pay...
Still.. with respect to what one CAN buy.. This is a great deal, and a great PSU.
The bag is pretty cheap, but with the proliferation of easily found teardown reviews, you can see many of the components they use in construction are actually expensive: form nice voltage regulators, to expensive name-brand capacitors, to large heatsinks and transformers.
Also, you can't really argue with results.
Sure, it's probably not as nice as a sony PSU I pulled out of a sun workstation, but I agree that it's a great deal on a great PSU.
Also, yeah, the bag probably didn't cost them much either. makes you feel all fancy when you open it up though.