Sorry, but we are no longer buying maps.
We were mapsellers or thirty years and have now retired.
Alas, we are unable to suggest prices or values for maps.
Some bookshops buy maps and charity shops should appreciate them. But you must choose the charity shop carefully. Why?
The 'high street chains' such as Cancer UK, Red Cross and Barnardos, generally seem only to have a bay of nice clean paperbacks and almost new hardback fiction. Take them some good, clean, but used Ordnance Survey maps or 1950s Penguin books and they are never seen in the shop. They vanish. Most appear to have 'a person who knows about books' come in and buy them.
No, when I suggest offering maps to a charity shop, I always say to find a local charity, a shop that looks more like a bric-a-brac shop than a fashion shop. The local animal centre, or town society charity shop. Any donation stands more chance of being on the shelves within days, than it would with a 'chain charity'. But even shops such as these must have 'contacts', who get to see and pick over recent donations before anyone else.
We hope that you will understand our position, and can find someone to take any maps you want to find a home for.