we gave away hundreds of books when we moved to our current place, and we gave away hundreds more when we moved to our last place. plus, i just sold a couple hundred books (some on ebay, some traded en masse to a bookstore for $5 or so apiece) this past winter. even the good stuff i sold, like my bukowski first editions, i haven't missed them. there are probably 100 books in my collection that i would never get rid of under any circumstances - and most of those are in that category because i have some personal history tied to the book and not necessarily because it's particularly valuable. i haven't counted, but that's probably around 15% of my collection. everything else i'll continue to own until it occurs to me that i haven't looked at it in a few years, at which point i'll move it out. i love downsizing - it's almost as good of a feeling (almost) as acquiring new stuff.