CJS CDKeys sells standalone office for ridiculously low prices. Windows version for 2021 is $23, and the Mac version is $37 (
Microsoft Office Home and Business 2021 CD Key for Mac - Instant Delivery at CJS CD Keys). This is a legitimate site - you get a real product key, and all installs are from downloads. I'm a Windows guy, so not sure if the Mac version will also install on an iPad - I know they have different OS's.