At post time, it’s back up to US$349. Price is on par with the BLU Pure XL.
I had no idea Sony went BLU-like with this phone and is selling it direct via Amazon.
Same-day update: Whoa. B&H Photo carries it, but no display model in store, dammit: Sony Xperia C5 Ultra E5506 16GB Smartphone (Unlocked, White). No luscious Mint color, but I’d want White over Black any day. More distinctive and visible from a distance (like when it gets misplaced at home!).
Next-day update: See Comments below post for an important Do Not Buy warning.