If you have an older device and want to upgrade to Windows 11 Pro and Microsoft Office Pro 2021, the combo is on sale for $49.97 right now (reg. $418). They both come with lifetime licenses.
Note that Microsoft Office Pro 2021 requires a PC to be updated to Windows 10 or 11, which is obviously solved if you’re upgrading to Windows 11 Pro at the same time. You can get both on sale for $49.97 right now (reg. $418) through October 7, though prices can change at any time.