If you specifically need a physical copy, these are available through marketplace sellers, though you should exercise caution regarding authenticity:
Windows 10 is officially no longer sold as a new retail product by major retailers like Best Buy. While you may find physical copies (on USB or DVD) through third-party sellers on Walmart or eBay , Microsoft recommends creating your own installation media using their free tool. Official Installation Media Creation windows 10 installation disc best buy
Instead of buying a physical disc, you can create a bootable USB drive or DVD yourself for free: If you specifically need a physical copy, these
: Can be found on Mercari for $30.00 (original price $175.00 ). Important Considerations these are available through marketplace sellers