You could consider a physical donation to the Internet Archive too, which is potentially more useful than a normal library because, as they say and I quote, they "try to digitize materials and make them available publicly as funding allows".

More info here: https://help.archive.org/help/how-do-i-make-a-physical-donation-to-the-internet-archive/

Literally 1984

In what region of the world are you located (it may help, as abroad shipping will most probably be over 100$). Beside that My first suggestion would have been to contact your local library but it's already covered so ;)

In the US you should be able to ship them 'media mail' which is extremely cheap.

I appreciate that you’re offering. I can’t home them because I’m already in trouble with [extremely long list of things my SO does not give two shits about]. But I love that you’re making the effort. Good on ya.

Are there any community centers, or rehabs in your area? Places like those can use books. An entire set like yours would be cool to see.

I already have 3 encyclopedias, stop temping me.