You might want to check out Gary Soto's books - they are published in both english/spanish- my girls like them.
Heres's a link for Penguin young reader books in spanish (they also have japanese lang. books) -they give you the isbn, so that way you can at least search or cross reference other sites like amazon, or AbeBooks.com, etc for pricing.
http://us.penguingroup.com/nf/Browse/BrowseStdPage/0,,263124,00.html
Good luck choosing #3!