Update 11/2/15: The old deal was short-lived, but a new one popped up. See the updated link below.
Update 11/16/15: The previous link is now showing $339.99, but a new seller has listed the blue variant for $289.99. Tax in NY, free shipping.
Right now everyone is drooling over the new Nexus 5X and Nexus 6P (especially since Android Police's exhaustive reviews of both went up this morning). But the Nexus 6 is still around, and it's still a fantastic phone, especially considering the crazy discounts we've been seeing lately. For example: this morning you can get a new 32GB model for just $289.99
from this eBay seller from this eBay seller from this eBay seller. That's more than $350 off of the original retail price from just a year ago, and it includes free shipping to the US.
Again, this particular phone is new, not refurbished, so it should come with the full warranty and the retail packaging. There's no sales tax unless you live in the seller's state. This is also the American model of the N6, which is cross-compatible with all five major carriers - just drop a nano-SIM card in and you're ready to go.
The N6 is still a great phone and it should run the latest versions of Android for at least another year. If you need a new device on the cheap, get an order in quickly.