I HATE how expensive it is! I know. Your books are probably free, but mine rarely are. The Dairy King cringes when he looks at our banking stuff on line and sees how much money we give the library in overdue fines. I try to tell him that I'm just doing my part in keeping the doors open up there, and it is still cheaper than buying all those books!
Here are some things I'm doing to combat that, though. . .
First of all, I let each girl pick 5 books each, so that's an easy number to remember.
I have a rule that all library books must stay in the school room. They can go in the school room anytime to read them, but no more pulling books from between walls and beds or other random places :)
The next thing is I lay all the books out and take pictures of them so if one does go missing we can figure out which one it is, and look for it with a picture in our minds of what we're looking for!
Here is the picture of our current stash (there are 12 because I got 2 books about ants for them).