Storage in or around Cambridge

Hi all. My wife and I have recently relocated to Cambridge and are now settling in. Since we are moving into something considerably smaller, we are now looking for a place to store some of our belongings (max 4 CBM of space needed). I have looked around the web, and am pretty amazed at the storage prices I have seen thus far, which start at 40 GBP per month for essentially nothing Protected content - if not less). Any hints/tips, or is storage just pricy?