We have had similar problems more do to early budget freezes. One way around it is to start a Birthday Book Club. If you're PTA/PTO will support the idea you ask for parents to "donate" an established amount of $$ and then purchase books with the funds. The nomey for the books is held by the PTA/PTO and I submit receipts for books purchased. We have a monthly celebration for the students in the "club" where we have a snack, sing happy birthday and then pick out a book from the collection I've purchased. The student has to have it approved by the parent before we add their name to the book and the catalog. We also place a bookplate in the book indicating it's a Birthday Book donated in honor of the student.
I'm happy to share our forms and ideas on this if anyone is interested. Last year we raised $3000 for new books!!!
The down side is I do not typically buy books to support curriculum; they are pleasure books.
Bev Bjorklund
Head O'Meadow Elementary School
Newtown, CT