Now that the third-generation Chromecast is available, it looks like Google and retail stores want to clear out inventory of the older model. At some Walmart locations, you can get a bundle of the second-gen Chromecast and a Google Home Mini for just $17. That's cheaper than either product would normally cost on their own.
Availability is limited, but you can check the BrickSeek link below to get an idea of which stores have it in stock. There are two locations near me with bundles still available, and other seem to have the bundle for $35 (which is still a decent deal). Your mileage may vary.