Take a look at scholastic; they sometimes have great sales on books.
Also, I sometimes get my kids fridge magnets from
www.vistaprint.com (Like: "Don't tell the other kids, but you're Mrs. Aliceacc's favorite!) or a picture of the cosmos with "Mrs. Aliceacc thinks you're a shining star!)
Then again, I teach secondary, so we're talking upwards of 180 kids-- some years I do it, some years I don't.
Or hit the dollar stores/Target and see if you can get some journals or diaries on sale-- something that will encourage writing.
Also, take a look at
www.orientaltrading.com