eBay and Mercari often have "New in Box" or "Like New" listings.
The original has been officially discontinued and replaced by the Google Nest Mini . While the Home Mini is no longer available directly from Google, you can still find it through secondary retailers and marketplaces. Where to Buy the Google Home Mini (1st Gen) where to buy google home mini
The Nest Mini is the current standard and is widely available at major retailers: Google Nest Mini - Smart Speaker for Any Room eBay and Mercari often have "New in Box"
Since this model is legacy hardware, your best bet is checking for remaining stock or certified pre-owned units: where to buy google home mini
Sites like Arbor occasionally offer deeply discounted legacy stock. Where to Buy the Google Nest Mini (2nd Gen)