It’s $150 for a “perpetual” license - but that’s not including any one drive storage. The Office 365 SaaS (I think now it’s Microsoft 365?) starts at $99/year.

I know this because I’ve been trying to find a solution for my sister who *absolutely needs* office to get a workable solution for Linux. Supposedly, she has to submit papers/writing as docx and can’t trust LibreOffice not to fuck up formatting.