I would LOVE to get my hands on some old SU catalogues! You can bet I DO save the ones I have, and use them too.
My back issues live in magazine holders on a shelf in my book case. I also have a clips file box. I sort and purge about once a year. There aren't too many recent issues in it - i haven't been impressed with the latest issues of any of the few remaining magazines. My older issues of Paper Kuts and Simple Scrapbooks though, still have a lot of relevance to my style.