Excel

That's good value. Is it kosher, works and with no bug? I'm on Chrome for the last 3 years.

My guess is the product key they sell you will work sometimes immediately, sometimes months later, sometimes not at all. For that price I guess it's going to be non-refundable. There are other 3rd party suppliers, more expensive but still a lot cheaper than an official license which will give you at least one replacement product key if the first one doesn't work. They get the product keys from various means e.g. extracted from stock of bankrupted companies or just bought off crooks.

Third party OEM keys are sold on the grey market. The important difference between them and retail keys is you can only use them once, so you cannot transfer them when you upgrade your laptop or even when you screw up and want to reinstall. The other important difference is they are a lot cheaper.

Most software vendors are moving to cloud and subscription models anyway.

Thank God for Apache Open Office and it's free to download...

https://www.openoffice.org/

@ramruma

That takes me back to the 90s and building my own PCs from motherboards and components from the shops and fairs that used to be at the bottom of Tottenham Court Road.  There were always stands with piles of DOS and Windows OEM disks and CDs with stuck-on licence keys.