Our local library had an extra book sale this year on Saturday, so of course we went. DOB went through the history and biography section and indulged in a few Louis L'Amours, while I went through children's fiction and D1 sat on the floor checking out a shiny book about racecars.
The main trouble with the library book sale is paring down the selection. In ordinary purchases, cost alone is a sufficient factor to keep our library from growing too exponentially (although it currently has outgrown not only the bookshelves but also the closet). But at $.25 a book, that's not enough. I can pass up the 73 copies of the Babysitter's Club well enough, along with Bert and Ernie Learn Numbers, but choosing which among the ones I might actually want my children to read are worth having around the house is a more difficult matter.
There are certain fiction authors I know by long experience are hard to find and worth picking up whenever you find them. I also figure it's worthwhile to make sure we have on hand paperback copies of classics I think they might actually want to read for fun, like Huckleberry Finn, even if we already have a bound edition. If I don't think a book looks likely to deserve a second read-through, I don't need to own a copy.
Non-fiction is even tougher. Who knows whether this very cool book on whales will ever appeal to any of them? And chances are there will be plenty of books on whales available at the library if any of them ever does get interested in whales. So I tried to limit myself to ones that had beautiful illustrations and that introduced a more general subject--like the desert, say, versus lizards. (But I did get the whale book.)
How do you all choose what books are worthy of owning and which should just be borrowed?