Unless you need a ton of storage on OneDrive, require some of its advanced (but less-used) functionality, or are worried about potential compatibility issues, paying for Office--either 365 or the standalone software--may not make much sense, at least for personal use. There are numerous robust and free productivity packages out there, such as LibreOffice and Open Office. Google Drive's productivity suite is plenty powerful for casual users and now packs decent offline functionality as well, though it's still an inherently cloud-based tool.
Sometimes paying for software is the only choice if you have specific need, but for more general usage, free alternatives can serve just as well. Give the no-cost alternatives a shot--what do you have to lose?
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