In truth, there is not much use for a set of printed encyclopedias these days, nor has there been for some time. 100 years ago they might have been the first set of secular books purchased in many homes. But in my lifetime their purpose seems to have been for kids to write school reports and that’s certainly not how kids go about such things today, except under duress.
So they take up space on your shelves with their black and white pictures, columns of static text, never updating themselves, nor linking to cats playing the piano. What to do?
I use a few carefully chosen sets to build bookcases and wall-hung shelves. (I build an armature out of recycled wood to fit the piece and veneer the books over that framework.) If you want me to do this with your books, I can make a wall shelf for as little as $150 when you provide the “lumber.”
I do collect older encyclopedias, typically pre 1970 editions with ornate spines that do not have large titles on their spines. Here are some examples of what I like. If you have such a set I would need to see a snapshot of the spines to know if I can use them. I’ll pay the shipping to get the right set, but I warn you, I have to be fussy about what I collect.