It is that time of the year where things get discounted.
Off the top of my head: Chromecast is $20 Chromecast Audio is $35 Chromecast Ultra is $54 Google Home Mini is $29
^^^ store.google.com
Walmart had a special:
Here's how you take advantage of the deal: you first buy a Google Home or Home Mini for their discounted $79 and $29 prices, respectively, at Walmart, Walmart.com, or on the Walmart store on Google Express. You activate your Home/Home Mini before January 15, 2018, and in the Home app, you link your Walmart account if you haven't done so already. Then you shop on the Walmart store on Google Express and you'll have a $25 promo code waiting for you at checkout. You'll need to use it before January 31, 2018.