Was it confirmed that $350 was a loss? I honestly don't know.
With 2 free third party games including a brand new $60 value one? You can bet on it. I'd be willing to bet they lost $50 per console sold minimum.
I don't get why people are surprised by the price returning to normal.
After all the big sales, even if they kept the promo the sales will tank anyway because they said it was limited in the first place (thus driving the potential Q1 buyers to purchase early "just in case").
Also, generally, you sell a product to make money, not to lose a bunch.
The insane promos (cumulating to a mind blowing $349 ACU bndle with $70 gc and another free game if memory serves) did their job by increasing both userbase and mindshare.
Time to see if the XB1 can swim on its own merits.