BlueBelle
Unfortunately if you have researched it and they are not worth money to you they won’t be worth anything to a charity shop either. If you saw how many books are sent off with the rag man every week you would weep
We do research most books to go on eBay or world of books but all the rest are sent to their death
First editions or books with a hand written message by the author will fetch some money but if you are looking on eBay you need to look at the ‘Sold section’ as they may be people who have estimated £20 but unless it sells for £20 it could be worthless
Checking in the 'sold' section of ebay is what I do. How other can you get the price the book sold for on ebay?
If the charity shop has someone who will take books, covers and all to recycle in some way, so much the better. You cannot put them in the paper recycling bins, so otherwise they go into the landfill/incinerator skips.