A4C offers the open-box 4th-generation Apple iPad 32GB WiFi + Unlocked 4G GSM Tablet with Retina Display in White, model no. MD520LL/A, for $369.95 with free shipping. That's tied with a September refurb mention in another color and the lowest total price we've seen for an unlocked 32GB iPad Retina. (It's also $110 under the best we could find for a new unit.)
It's not guaranteed for arrival by Christmas.