Amazon has the Motorola Moto X4 Prime edition for pre-order at $329.99,
That's $70 off retail, and a littler better than the $50 they usually do- as long as you do not mind the ad lock screen.
You can also get it in either color which is a nice change (Amazon normally only had one color as Prime version)
Cheapest new phone you may
(not sure if it is Andriod One) be able to bring into Google Fi