今早在reddit看到
StackSocia過去很多人有分享過，應該算是滿可靠的站
https://www.reddit.com/r/blackfriday/comments/z33sij/stacksocial_us_microsoft_office_2021_lifetime/
https://stacksocial.com/sales/microsoft-office-professional-2021-for-windows-lifetime-license-4?aid=a-x8krt9c9
StackSocial has select Microsoft Office 2021 Lifetime License (Digital
Download) on sale for $29.99.
Available:
Microsoft Office Professional 2021 Lifetime License (Windows Digital
Download) $29.99
Microsoft Office Home & Business for Mac 2021 (macOS Digital Download) $29.99